



















QUANTITATIVE 

METALLURGICAL 


ANALYSIS 



QUANTITATIVE METAL- 
LU RGICAL ANALYSIS 


r 


SELECTED METHODS FOR 
CHEMICAL ANALYSIS OF ORES, 
SLAGS, COAL, IRON AND STEEL 


Arranged by 

CHARLES FREDERICK SIDENER, B. S. 

\\ 

Professor of Chemistry, University of Minnesota 



The H. W. WILSON COMPANY 
MINNEAPOLIS 
1907 




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PREFACE TO THE SECOND EDITION 


This book is primarily intended for the use of the 
students in Metallurgical Analysis at the University of 
Minnesota. 

The aim has been to give in a condensed form what 
the writer considers, after several years of experience in 
teaching the subject, the best technical methods for the 
analysis of ores of the most common metals, furnace 
products, coal and coke. 

A course of lectures is given in connection with the 
laboratory work, the purpose being to educate the stu¬ 
dent in a scientific way of thinking and working, as well 
as to train him to use a number of technical methods. 

The writer desires to acknowledge his obligation to 
the authors of the standard reference works mentioned 
in the text, and articles in the scientific journals which 
have been made use of in compiling this lit'tle manual. 
Credit for the various procedures has been given in many 
instances, but it has not been possible to do so in every 
case. 


BOOKS OF REFERENCE. 

C. R. Fresenius—Quantitative Analysis. 

' 0 

F. Cairns—Quantitative Analysis. 

H. Furman—A Manual of Practical Assaying. 

A. A. Blair—The Chemical Analysis of Iron. 

N. W. Lord—Notes on Metallurgical Ana'ysis. 

M. Trolius—Notes on the Chemistry of Iron. 

J. O. Arnold—Steel Works Analysis. 

F. C. Phillips, Ed.—Methods of Iron Analysis in the 
Laboratories about Pittsburg, Pa. 

A. H. Low—Technical Methods of Ore Analysis. 


VOLUMETRIC IODIDE METHOD FOR THE DE¬ 
TERMINATION OF COPPER IN 
COPPER ORES. 

Modified by A. H. Low. 

The method depends upon the following - reaction: 

2Cu(CoHo0 2 ) 2 +4Ki=CuJ 2 -1-4KC 2 H. 5 0o+I 2 . 
Cuprous iodide precipitates and a proportionate amount 
of iodine is set free, which may be determined by titra¬ 
tion with sodium thiosulphate. The reaction is: 

2Na 2 S 2 0 3 +2l—2NaI+Na 2 S 4 O e 

The standard solution required is that of sodium thio¬ 
sulphate which may be prepared by dissolving 19.59 
grams of the pure salt in a liter of water, and standard¬ 
izing as follows: 

Weigh out into two flasks of 200-300 c.c. capacity two 
portions of copper foil of about 0.2 grams each. Dissolve, 
by warming with 5 c.c. of dilute nitric acid (sp. gr. 1.2). 
Boil for a few moments to partially expel the red fumes 
and then add 5 c.c. of strong bromine water and boil un¬ 
til the bromine is thoroughly expelled, but do not evap¬ 
orate to such an extent as to decompose the bromides. 
The bromine is to insure the complete destruction or re- 


2 


METALLURGICAL ANALYSIS 


moval of the red fumes. Remove from the heat and 
treat the solution by one of the following methods to 
change the copper into the form of copper acetate, (a) 
Add a slight excess of ammonia water and boil until the 
excess of ammonia is expelled, as shown by a change of 
color of the liquid and a partial precipitation of the cop¬ 
per as hydroxide or oxide. Now add strong acetic acid 
in slight excess, perhaps 3 or 4 c.c. of the 80 per cent, 
acid in all, and boil again for a moment if necessary to 
redissolve the copper, (b) Add 20 c.c. of a cold satu¬ 
rated solution of zinc acetate and heat the solution to 
boiling, (c) Add sodium carbonate till a permanent pre¬ 
cipitate occurs and then acetic acid until the precipitate 
dissolves, and heat the solution to boiling. Free min¬ 
eral acids decompose the iodide of potassium, therefore 
no free acid stronger than acetic should be present. The 
condition is attained by any one of the above methods. 
Cool the solution to the ordinary temperature, and dilute 
with water to about 50 c.c. Add 3 grams of potassium 
iodide and shake gently until the salt dissolves. Titrate 
the solution immediately with the thiosulphate until the 
brown color is nearly destroyed. Add 1 or 2 c.c. of 
starch solution, and continue the titration until the blue 
color disappears. Calculate the strength of the thiosul¬ 
phate solution in terms of copper. 

Process .—Treat one gram of the pulverized ore in a 
covered casserole, under a hood, with 7 c.c. of concen¬ 
trated nitric acid and gently heat for a few moments; 
add five c.c. of concentrated hydrochloric acid and again 
heat for a short time. Then add five c.c. of concentrated 
sulphuric acid and evaporate until dense fumes of sul¬ 
phuric anhydride are evolved. Cool; add 50 c.c. of water 


METALLURGICAL ANALYSIS 


3 


and heat until the sulphates of copper, iron, etc., have 
dissolved. Filter into a small beaker, wash with a little 
hot water and endeavor to keep the volume of the filtrate 
down to about 50 or 60 c.c. 

Place in the beaker two pieces of aluminium about Ip2 
inches square, 1 / 16 inch thick, with the four corners bent 
for Ft inch alternately up and down at right angles. Add 
five c.c. of concentrated sulphuric acid, cover the beaker 
and heat to boiling. Boil for eight or ten minutes. Un¬ 
less the bulk of the solution is excessive, this will gener¬ 
ally be sufficient to precipitate all of the copper. Trans¬ 
fer the solution to a flask of 200 to 300 c.c. capacity, 
rinsing in with hot water, as much of the copper as pos¬ 
sible. Allow the copper in the flask to settle and decant 
the liquid through a filter, wash the copper two or three 
times, retaining it as completely as possible in the flask. 
Pour upon the aluminum in the beaker five c.c. of dilute 
nitric acid (sp. gr. 1.2) warm gently until the copper is 
dissolved. Then pour the solution through the filter, re¬ 
ceiving tfie filtrate in the flask containing the main por¬ 
tion of the copper. At this stage do not wash either the 
aluminum or the filter, but simply remove the flask and 
set the beaker in its place. 

ITeat the contents of the flask to dissolve the copper; 
add 5 c.c. of strong bromine water and boil for a moment 
to oxidize any arsenic present to arsenic acid. Remove 
the flask from the lamp and again place it under the fun¬ 
nel. Now wash the beaker, aluminium and filter with as 
little hot water as possible. Boil to remove the excess 
of bromine but avoid boiling to such a small bulk as to 
cause decomposition of bromides, etc. 

Change the copper into the form of copper acetate, 


4 


METALLURGICAL ANALYSIS 


add about 3 grams of potassium iodide and titrate with 
the thiosulphate precisely as described above in the stand¬ 
ardization of the thiosulphate. 


References on sampling ores: 

Wm, Glenn, Trans. Am. Inst. Min. Engs., Vol. XX, page 155. 
Rattle and Nye, Jour. An. cC- App. Chem., Vol. V., page 
N. W. Lord, Notes on Metallurgical Analysis. 

A. A. Blair, The Chemical Analysis of Iron. 


References on copper : 

H. Furman, A Manual of Practical Assaying. 

A. II. Low, Jour. Am. Chem. Soc., Vol. XVIII, page 458. 

A. H. Low, Jour. Am. Chem. Soc., Vol. XXIV, page 1082. 


VOLUMETRIC DETERMINATION OF COPPER 
BY POTASSIUM CYANIDE SOLUTION. 

The method depends upon the fact that the addition 
of potassium cyanide to an ammoniacal copper solution 
affords a colorless solution. The reaction is: 

2 Cu(NH 3 ) 4 (N 0 3 )oH 2 0 + 8 KCN= 

[Cu 2 (CN) e ]K 4 +NH 4 CN 0 +NH 4 CN+ 6 NH 3 + 4 KN 0 8 

The standard solution required is potassium cyanide, 
which may be prepared as follows: Dissolve 20 grams of 
potassium cyanide in a half-liter of water and thoroughly 
mix. To standardize, weigh out into two flasks, of 200 
to 300 c.c. capacity, two portions of pure copper foil of 
about 0.3 grams each. Dissolve these in 5 c.c. of con¬ 
centrated nitric acid; boil off the red fumes, dilute 
slightly, add 10 c.c. of ammonium hydroxide (sp. gr. .9), 
cool, dilute with water to about 100 c.c. and titrate with 
the potassium cyanide solution until within a few cubic 
centimeters of the end, when the bulk of the solution 


METALLURGICAL ANALYSIS 


5 


should be noted and distilled water added, if necessary, 
so that the final bulk will be about 180 c.c. Continue the 
titration slowly, the flask being shaken after each addi¬ 
tion, until the blue or lilac tint can scarcely be discerned 
at the upper edge of the liquid, when viewed against a 
white background. Some chemists titrate to a faint rose 
or pink tint. Calculate the strength of the cyanide so¬ 
lution in terms of copper. 

Process —Treat one gram of the pulverized ore in a 
covered casserole with 7 c.c. of concentrated nitric acid 
and gently heat for a few moments; add five c.c. of con¬ 
centrated hydrochloric acid and again heat for a short 
while. Then add 5 c.c. of concentrated sulphuric acid 
and evaporate under a hood until dense fumes of sul¬ 
phuric anhydride are evolved. Cool; add 50 c.c. of water 
and heat until the sulphates of copper, iron, and so forth, 
have dissolved. Transfer the contents of the casserole 
to a flask of 200 to 300 c.c. capacity, and add 6 grams of 
sheet zinc, and allow to stand until the copper is com¬ 
pletely precipitated. If the action is too slow the flask 
may be gently heated. Next add 50 c.c. of water and 20 
c.c. of concentrated sulphuric acid to rapidly dissolve the 
excess of zinc. When the solution of the zinc is com¬ 
plete dilute with water up to the neck of the flask; allow 
to settle, and decant the clear supernatant liquid; fill up 
with water and decant twice more. To the residue in the 
flask, add 5 c.c. of concentrated nitric acid, and boil to 
expel red fumes. Dilute with a little water, add 10 c.c. 
of ammonium hydrate (sp. gr. .9), cool, dilute with water 
to about 100 c.c. and filter if necessary. Wash the resi¬ 
due with a little water and titrate the copper solution 
with a standard cyanide solution. When near the end 


6 


METALLURGICAL ANALYSIS 


dilute to iSo c.c. and finish the titration as described 
above. 


Reference: Geo. Ellis. Jour. Soc. Ghent. Industry, Vol. VIII, 
page 086. 


ELECTROLYTIC DETERMINATION OF COPPER 

IN COPPER ORES. 

Treat one gram of the pulverized ore in a covered cas¬ 
serole, under a hood, with 2 c - c - of concentrated nitric 
acid and heat for a few moments, add 5 c.c. of concen¬ 
trated hydrochloric acid and again heat for a short time. 
Then add 5 c.c. of concentrated sulphuric acid and evap¬ 
orate until dense white fumes of sulphuric anhydride are 
evolved. Cool, add 50 c.c. of distilled water and heat 
until sulphates of copper, iron, etc., have dissolved. Fil¬ 
ter into a weighed platinum dish and wash the residue 
with a little hot water. Connect the dish with the nega¬ 
tive pole of a Bunsen battery of two cells or its equiva¬ 
lent. The current used should be of such a strength 
that it will decompose water at the rate of 3 to 4 c.c. of 
oxyhydrogen gas per minute. Place in the solution a plat¬ 
inum plate or spiral, connected with the positive pole of 
the battery. The copper is deposited upon the dish and 
generally requires from five to ten hours for complete de¬ 
position. When the precipitation of the copper appears 
to be complete, take about 2 or 3 c.c. of the solution out 
by means of a pipette and test it with a slight excess of 
ammonia. If copper is found, return the portion tested 
to the dish, and continue the electrolysis. If no blue color 
is produced with ammonia the copper is all deposited 


METALLURGICAL ANALYSIS 


7 


Quickly remove the platinum spiral or plate and empty 
the dish, and wash it two or three times very carefully 
with distilled water, and then two or three times with al¬ 
cohol, to wash out all of the water. Dry the dish and 
contents for a few seconds in the drying oven at about 
105° C. Cool in a desiccator and weigh. 

A platinum cone may be used for the negative elec¬ 
trode instead of the platinum dish. Have the copper so¬ 
lution in a beaker of about 75 c.c. capacity. Place in the 
solution the platinum cone and platinum spiral, connect 
the cone with the negative pole of the battery and the 
platinum spiral with the positive pole and continue the 
electrolysis as above. 


COLOR METHOD FOR COPPER. 

.This method is often used for the estimation of copper 
in substances containing less than 2 per cent, of copper, 
e.g. in slags from copper smelting operations, and in tail¬ 
ings from concentrating works. The method consists in 
converting the copper in a substance to be tested, into 
ammonia-copper-nitrate and comparing the blue color 
produced with that produced by dissolving the same 
amount of a standard copper ore, in the same amount of 
acid and using the same amount of ammonia as is used 
in the sample to be tested. 

Process —Weigh out the same amount of sample and 
standard, and treat with acids as described in the cyanide 
process, and then precipitate it with zinc. The copper is 
washed by decantation, dissolved in about 2 c.c. of nitric 
acid and an excess of ammonia (about 4 c.c. sp gr. .9) 


8 


METALLURGICAL ANALYSIS 


added. Dilute with water, and filter if necessary, into 
the comparison tubes. 

Reference: T. Carnelly, Clicm. News, Vol. XXXII, page 308. 


TECHNICAL DETERMINATION OF ZINC IN 
ORES—POTASSIUM FERROCYANIDE METHOD. 

Modified by A. H. Low. 

Preparation of Standard Fcrrocyanide Solution —Dis¬ 
solve 22 grams of potassium ferrocyanide crystals in 
water and dilute to one liter. Weigh carefully about o i 
gram of pure zinc and dissolve in six c.c. of strong hy¬ 
drochloric acid, using a 400 c.c. beaker. Then add about 
10 grams of ammonium chloride and 200 c.c. of boiling 
water. Titrate with the ferrocyanide solution The re¬ 
action is: 

2ZnCl 2 +K 4 FeCn 0 =Zn 2 FeCn 6 -|-4KCl. 

Continue the titration until a drop, when tested on a por¬ 
celain plate with a drop of strong solution of uranium 
nitrate, shows a brown tinge. The reaction is: 

K 4 FeCn 6 -|-2Uo 2 (No 3 ) 2 = (Uo 2 ) 2 FeCn 6 +4KN0 3 . 
When the titration is about finished, the reaction is much 
sharper if several drops are placed in the depression of 
the plate and tested with a drop of uranium nitrate. As 
this is near the end of the titration the amount of zinc 
lost by it is insignificant. As soon as a brown tinge is 
obtained, note the reading of the burette and then wait a 
minute or two and observe if one or more of the preced¬ 
ing tests do not also develop a tinge. The end point is 


METALLURGICAL ANALYSIS 


9 


usually passed by a test or two and the burette readings 
must be accordingly corrected. A further correction 
must be made for the amount of ferrocyanide required to 
produce a tinge under the same conditions when no zinc 
is present. This is only one or two drops. One c.c. of 
the standard solution will equal about .005 gram of zinc 
or about one per cent, when 0.5 gram is taken for analy¬ 
sis. 

Assay of Ores. 

To 0.5 gram of the pulverized ore in a 250 c.c. pear- 
shaped flask, add about 2 grams of potassium nitrate and 
5 c.c. of strong nitric acid. Heat until the acid is about 
half gone and then add 10 c.c. of a cold saturated solution 
of potassium chlorate in strong nitric acid and boil to 
complete dryness. Avoid overheating and baking. It is 
usually necessary to manipulate the flask in a holder over 
a naked flame to avoid loss by bumping. The boiling 
may be conducted rapidly, and toward the end it is best 
to heat the entire flask so as to expel every trace of liquid. 
The potassium nitrate serves simply as a diluent of the 
dry residue and insures the completeness of the subse¬ 
quent extraction of the zinc. Cool sufficiently and add 
30 c.c. of a prepared ammoniacal solution and heat to 
boiling. This solution is made by dissolving 200 grams 
of ammonium chloride in a mixture of 500 c.c. of strong 
ammonia water and 350 c.c. of water. 

Boil the contents of the flask gently for about two min¬ 
utes and then filter through a 9 c.m. filter and wash with 
a hot solution of ammonium chloride containing about 
100 grams of the salt and 50 c.c. of strong ammonia 
water to the liter. Collect the filtrate in a 400 c.c. beak¬ 
er. Place a bit of litmus paper in the filtrate (not neces- 


10 


METALLURGICAL ANALYSIS 


sary if much copper is present) and neutralize carefully 
with hydrochloric acid, finally adding 6 c.c. of the strong 
acid in excess. Dilute to about 150 c.c. and add 50 c.c. 
of a cold saturated solution of hydrogen sulphide. Heat 
nearly to boiling and titrate with standard potassium 
ferrocyanide solution. Make corrections of burette read¬ 
ings as in standardization. 

A r otes .—If the ore contains considerable arsenic give it 
a preliminary treatment as follows:—To 0.5 gram of ore 
in the flask add 10 c.c. of strong hydrochloric acid and 
one c.c. of bromine. Warm gently for several minutes 
to decompose the ore without loss of bromine, and then 
boil rapidly to complete dryness. The arsenic will then 
be sufficiently expelled. Now add the potassium nitrate 
and nitric acid and proceed as above. If the ore con¬ 
tains much copper and cadmium it may be necessary to 
pass a current of hydrogen sulphide gas into the hot so¬ 
lution to precipitate them instead of using the water so¬ 
lution of the hydrogen sulphide. If the precipitate is 
very large it had better be filtered off and the filtrate ti¬ 
trated as usual. 

In ores containing copper but no cadmium, the copper 
can be best precipitated with test lead without the use of 
hydrogen sulphide as follows: After neutralizing the 
ammoniacal filtrate from the insoluble residue acidify 
with an excess of 10 c.c. of concentrated hydrochloric 
acid and add about 30 grams of test lead. Heat nearly 
to boiling and stir the lead about until the copper is all 

precipitated. Now dilute to 200 c.c. and titrate as de¬ 
scribed without removing the lead and precipitated cop¬ 
per. 

References: 

Jour. An. & App. Chem., Vol. XI. page 401. 

A. H. Low, Jour. Am. Cliem. Soc., Vol. XXII, page 19S. 


METALLURGICAL ANALYSIS 


ii 


Modified Waring Method. 

To 0.5 gram of the pulverized ore in a porcelain casse¬ 
role, add 10 c.c. of concentrated hydrochloric acid, mix 
thoroughly, and boil nearly to dryness. Then add 10 c.c. 
of concentrated nitric acid and again boil nearly to dry¬ 
ness. Next add 10 c.c. of concentrated sulphuric acid 
and evaporate until very dense fumes of sulphur trioxide 
are evolved. Cool, add about 50 c.c. of water and heat. 
Place in the solution a piece of aluminum and boil 10 
minutes, or to complete reduction of the iron and pre¬ 
cipitation of the lead, copper, cadmium and bismuth. Fil¬ 
ter and wash through a filter containing a piece of alum¬ 
inum into a beaker containing £.11 aluminum stirring rod 
or strip of aluminum, cool, add a drop or two of methyl 
orange, nearly neutralize the solution with sodium hy¬ 
droxide and then finish the exact neutralization with sod¬ 
ium bicarbonate. Add, dropwise, dilute formic acid (20 
per cent, strength) until the pink color is just restored, 
then 5 drops more. (Dilute hydrochloric acid, one part 
strong acid to 6 parts water, may be substituted for 
formic acid when ammonium sulphocyanate is to be in¬ 
troduced). Dilute to about 100 c.c. for each 0.1 gram 
Zn presumably present, add, if much iron is present, 2 
to 4 grams ammonium sulphocyanate. Remove the strip 
of aluminum, heat nearly to boiling and saturate with 
hydrogen sulphide. 

Allow the pure white Zinc sulphide to subside for a 
few minutes, then filter and wash with hot water. Trans¬ 
fer the precipitate and filter to a capacious beaker, heat 
with 8 or 10 c.c. of strong'hydrochloric acid and 30 or 40 
c.c. of water until the zinc is all in solution. 


12 


METALLURGICAL ANALYSIS 


Determine the zinc either gravimetric ally by weighing 
as a pyrophosphate or volumetrically by titrating with a 
standard solution of potassium ferrocyanide. 

References : 

G. Waring, Jour. Am. Chem. Soc., Vol. XXVI, page 4 . _ 

G. C. Stone and G. Waring, Jour. Am. Chem. Soc., Vol. XXIX, 
page 202. 

DETERMINATION OF LEAD IN LEAD ORES. 

VOLUMETRIC METHOD—ALEXANDER'S. 

This method is based on the fact that ammonium mo¬ 
lybdate when added to a hot solution of lead acetate will 
give a precipitate of molybdate of lead PbMo 0 4 , which 
is insoluble in acetic acid. An excess of ammonium mo¬ 
lybdate will give'a yellow color with a freshly prepared 
solution of tannin. 

Solution Required. —A standard solution of ammon¬ 
ium molybdate containing about nine grams of salt per 
liter. If the solution is not clear, add a few drops of 
ammonia. 

Indicator. —A freshly prepared solution of one part of 
tannin to 300 parts of water. 

f 

Standardicing. —Weigh out .3 gram of pure dry sul¬ 
phate of lead, dissolve it in hot ammonium acetate, acid¬ 
ify with acetic acid and dilute with water to 250 c.c.; 
heat to boiling and run in from a burette the ammonium 
molybdate solution till the lead is all precipitated as white 
PbMo 0 4 . This is ascertained by placing drops of indi¬ 
cator on the porcelain plate and to them add a drop of 
the solution tested after each addition of molybdate. 
When the end is reached the excess of ammonium molyb- 


METALLURGICAL ANALYSIS 


13 


date gives a yellow color with tannin. The excess neces¬ 
sary to affect the indicator (about .7 c.c.) must be deter¬ 
mined and subtracted from the burette readings. In ti¬ 
trating it is essential to stir the solution very thoroughly, 
and when near the end to wait a few seconds before try¬ 
ing the drop test. 

Process .— 

Dissolve one gram of the finely pulverized ore in 15 
c.c. of concentrated nitric acid in a covered casserole by 
the aid of heat. Partly cool and add 10 c.c. of sulphuric 
acid of sp. gr. 1.41, and evaporate till fumes of sulphuric 
anhydride appear. Allow to cool and then decant thru 
a small filter, leaving as much of the lead sulphate, silica, 
etc.., as possible in the casserole. Wash thoroughly with 
dilute sulphuric acid, then once with water. Dissolve the 
lead sulphate from the residue, in the casserole, in a 
strong hot solution (200 grams per liter) of ammonium 
acetate, slightly acid with acetic acid. Pour this solution 
through the filter into a clean beaker and repeat this until 
all the lead sulphate is dissolved, then wash the contents 
of the casserole onto the filter with hot water. Acidify 
the filtrate with acetic acid, dilute to 250 c.c. with hot 
water and heat to boiling. The solution is now ready for 
titration, which is done as in standardizing. 

Consult: H. Furman, A Manual of Practical Assaying. 

DETERMINATION OF ARSENIC IN ORES 
AND METALLURGICAL PRODUCTS. 
candy’s modification of pearce's method. 

Mix 0.5 gram of the pulverized ore with about eight 


14 


METALLURGICAL ANALYSIS 


times its weight of a mixture of equal parts of sodium 
carbonate and potassium nitrate, in a large porcelain 
crucible. Heat gradually up to fusion, and keep so for 
five minutes or more. Cool, treat with boiling water, fil¬ 
ter off the insoluble residue and wash it with hot water. 
Acidify the filtrate with dilute nitric acid and boil off the 
carbonic and nitrous acid gases. Add an emulsion of 
zinc oxide until it can be seen in some excess in the bot¬ 
tom of the beaker after stirring vigorously and then al¬ 
lowing a few moments to settle. Should an unusually 
heavy precipitate of gelatinous silica and alumina be pro¬ 
duced, filter, wash and add more emulsion to the filtrate. 
Now add a slight excess of silver nitrate, stirring vigor¬ 
ously to precipitate the silver as silver arsenate, Ag. 5 As 0 4 . 

Filter and wash with cold water. Now place the beak¬ 
er in which the precipitation was made, under the fun¬ 
nel, and dissolve off the precipitate with dilute nitric 
acid, and wash with cold water. Cool the solution, and 
titrate the silver with standard solution of potassium or 
ammonium sulphocyanate, using i c.c. of a saturated so¬ 
lution of ferric sulphate as indicator. 

With potassium sulphocyanate, the following are the 
reactions: 

AgN 0 3 +KSCN=AgSCN+KN 0 3 and 
6KSCN-fFe 2 (S0 4 ) 3 =2Fe(SCN) 3 + 3 K 2 S0 4 . 

Add the sulphocyanate solution from a burette until a 
faint amber yellow color can be seen in the solution after 
vigorous stirring. 

\ 

PREPARATION AND STANDARDIZATION OF THE SUL¬ 
PHOCYANATE SOLUTION. 

Dissolve 5 or f> grams of the potassium or ammonium 


METALLURGICAL ANALYSIS 


15 

sulphocyanate in a liter of water and mix thoroughly. 
The solution is standardized by dissolving 0.3 or 0.4 gram 
of pure silver in nitric acid, boiling to expel red fumes, 
diluting to about 100 c.c. and titrating with the sulpho¬ 
cyanate solution, using 1 c.c. of the ferric sulphate (or 
ferric alum) as indicator. Calculate the strength of the 
solution in terms of arsenic. 

Note Bennett's Modification of the Pearce Method — 
Decompose the ore by fusion, treat with water and filter 
off the insoluble residue. Acidify the filtrate strongly 
with acetic acid; cover and boil rapidly for a few minutes 
to expel carbonic acid. Cool and add a few drops of 
phenolphthalein, then sodium hydrate to just alkaline re¬ 
action, then one or two drops of acetic acid, which will 
discharge the purple red color if too much hydroxide has 
not been used. The volume of the solution should now 
be about 100 c.c. Add in slight excess while violently 
agitating with a stirring rod, a neutral solution of silver 
nitrate and allow to settle for a few minutes. Filter, 
wash the precipitate with cold water, dissolve it in dilute 
nitric acid and cool. Dilute to about 100 c.c. and ti¬ 
trate the silver with a standard sulphocyanate solution, 
using 1 c.c. of ferric sulphate as indicator. Calculate per 
cent. As. 

References : 

A. H. Low, Chcm. News, Vol. XLVIII. page 85. 

L. M. McCay, Chem. News, Vol. XLVIII. page 7. 

Canby, Trans. Am. Inst. Min. Engs., Vol. XVII, page 77. 

R. Pearce, Proc. of the Colo. ISci. Soc.. Vol. I. 

J. F. Bennett, Jour. Am. Cliem. Soc., Vol. XXI, page 431. 

DETERMINATION OF CHROMIUM IN CHROME 

IRON ORES. 

METHOD OF A. G. MCKENNA. 

Weigh 0.5 gram of the finely ground ore in a nickel or 


16 METALLURGICAL ANALYSIS 

iron crucible. Mix with the ore three or four grams of 
sodium peroxide. Hold the crucible over a Bunsen burn¬ 
er by means of a pair of tongs and heat until fusion be¬ 
gins. Keep the mass in a liquid condition at a low red 
heat for about five minutes. Cool, then place crucible 

and contents in a number four beaker and add hot water 

* 

to cover the crucible. Cover the beaker with a glass cover 
and keep warm until the fusion dissolves. The chrom¬ 
ate passes into solution, and the ferric hydroxide remains 
undissolved. Remove the crucible; and heat the solu¬ 
tion to boiling for fifteen minutes. Allow the liquid to 
cool for a moment, then acidify with dilute sulphuric 
acid adding i c.c. in excess of the amount necessary to 
dissolve the ferric hydroxide. The sulphuric acid con¬ 
verts the sodium chromate to sodium bichromate. 

The reaction is: 

2 Na 2 Cr 0 4 +H 2 S 0 4 =Na 2 Cr 2 0 7 +Na 2 S 0 4 +H 2 0 . 

Dilute the solution with cold water to about 300 c.c. 
and add 70 c.c. of ferrous sulphate solution prepared as 
follows: Dissolve 25 grams of ferrous sulphate crystals 
in water to which has been added 10 c.c. of dilute sul¬ 
phuric acid. Dilute the solution to 500 c.c. and mix thor¬ 
oughly. The reaction between the sodium bichromate 
solution and ferrous sulphate in presence of sulphuric 
acid is as follows: 

Na 2 Cr 2 0 7 +6FeS0 4 +7H 2 S0 4 = 

3Fe 2 (S 0 4 ) 3 +Cr 2 (S 0 4 ) 3 +Na 2 S 0 4 + 7 H 2 0 . 
Now determine the excess of ferrous sulphate which has 
been added by means of a standard solution of potassium 
permanganate (or potassium bichromate). 

Determine the exact strength of the ferrous sulphate 


METALLURGICAL ANALYSIS 


1 7 


solution as follows: Run out from a burette into a beaker 
about 30 c.c. of the ferrous solution; add about 10 c.c of 
dilute sulphuric acid; dilute to about 150 c.c. and run in 
the permanganate from the other burette until the pink 
color becomes permanent. Calculate the amount of iron 
oxidized by the chromium from the chrome ore and then 
the weight of chromium in solution and the percentage in 
the ore. 

References : 

E. H. Saniter, Jour. Soc. Chem. Ind., 1896, page 155. 

Genth, Chem. News, Yol. VI, page 31. 

Kennicutt & Patterson, Jour. An. & App. Chem., Vol. III., page 
132. 

.T. Massignon, Jour. An & App. Chem,, Vol. V. page 465, 

A. G. McKenna, Proc. Eng. 8oc. Western Pa., 1896 & 1897. 

F. C. Phillips, Ed., Methods of Analysis in the Laboratories 

Around Pittsburg, Pa. 

PARTIAL ANALYSIS OF SLAG. 

Silica .—Weigh out .5 to 1 gram of the pulverized slag 
into a casserole. Decompose with hydrochloric acid and 
a little nitric acid and evaporate to complete dryness. 
Moisten the residue with concentrated hydrochloric acid 
and allow to stand in a warm place for about ten min¬ 
utes. Then add water, heat to boiling, filter, and wash 
alternately with dilute hydrochloric acid and cold water. 
Evaporate the filtrates to complete dryness in a porcelain 
casserole, moisten the residue with concentrated hydro¬ 
chloric acid and allow to stand in a warm place for a few 
minutes. Then add water, heat to boiling, filter off the 
remaining silica, and wash it alternately with dilute hy¬ 
drochloric acid and cold water. Ignite the wet filters 
containing the silica, cool, and weigh. 

If BaS 0 4 is present treat with hydrofluoric acid and 
get the silica by loss in weight. 


i8 


METALLURGICAL ANALYSIS 


Barium .—Treat another portion of from .5 to 1 gram 
with hydrochloric and a little sulphuric acid. Evaporate 
to dryness, heat until fumes of sulphuric anhydride ap¬ 
pear. Add water, and hydrochloric acid, heat, filter, 
wash with hot water, ignite and weigh Si 0 2 -|-BaS 0 4 . 
Subtract from this the Si 0 2 as determined above to get 
Ba S 0 4 . 

Lime .—Method I.—Heat the filtrate from the silica to 
boiling, add ammonia in slight excess, and then a strong- 
solution of oxalic acid in excess to dissolve the iron and 
aluminum precipitate. Heat the solution to boiling to 
precipitate calcium oxalate. Allow to stand for a short 
time to settle, then filter and wash thoroughly with hot 
water. Place the funnel over a clean beaker, and by 
means of a glass rod make a hole in the filter, and wash 
the precipitate through the funnel into the beaker. Wash 
the filter paper with a little hot dilute sulphuric acid. If 
the sulphuric acid fails to dissolve the last traces of the 
calcium oxalate a little hydrochloric acid may be used, 
and the filter paper again washed with hot water. 

The reaction is CaC 2 0 4 +H 2 S 0 4 ==CaS 0 4 --f-H 2 C 2 0 4 
Dilute the solution to about 100 c.c. Add about 15 c.c. 
of dilute sulphuric acid, heat to about /0°C. and titrate 
the oxalic acid with standard permanganate solution. 
Calculate the per cent, of CaO. 

Note .—Tartaric acid may be used instead of oxalic 
acid to dissolve the hydroxides of iron and aluminum, and 
the calcium then precipitated with ammonium oxalate. 
This method is not satisfactory if the slag contains more 
than 0.5 per cent, of manganese. 

Method II.—Treat one gram of the pulverized slag 
with water and hydrochloric acid. Boil gently until the 


METALLURGICAL ANALYSIS 


19 


slag is decomposed. Dilute the liquid, nearly neutralize 
the acid with ammonia. Make a basic acetate precipita¬ 
tion, filter and determine the calcium in the filtrate as fol¬ 
lows : concentrate the solution and precipitate the cal¬ 
cium with ammonium oxalate. Determine the lime vol- 
umetrically as in method I. 

Note .—If much manganese is present the calcium ox¬ 
alate must be redissolved and reprecipitated before mak¬ 
ing the titration. Or the manganese may be precipitated 
with bromine and filtered off before adding the ammon¬ 
ium oxalate. 

Magnesia. —may be determined in the filtrate from the 
calcium oxalate by precipitation with hydrogen sodium 
phosphate in presence of an excess of ammonia. 

Iron, Lead, Copper , Manganese, Zinc —Follow the 
methods described in the notes on the analyses of vari¬ 
ous ores, taking separate portions for each. 

ANALYSIS OF IRON BLAST-FURNACE SLAG. 

In taking a sample of slag from a furnace for analysis 
it is the custom to suddenly chill the slag in some way in 
order to render it soluble in acid. This may be done by 
pouring the hot slag into water, or by dipping a cold 
steel rod into the fluid slag and quickly removing it with 
some of the slag adhering to it. The slag so chilled will 
have a glassy appearance, and unless it contains more 
than 40 or 45 per cent of silica, it will dissolve quite com¬ 
pletely in acid. 

The first step in the process of analysis is the decom¬ 
position of the slag, and the method used will depend 
upon whether the slag can be entirely or but partially de- 


METALLURGICAL ANALYSIS 


20 

composed by hydrochloric acid. If a preliminary test 
on some of the finely pulverized slag shows it to be sol¬ 
uble or very nearly so in warm dilute hydrochloric acid, 
then proceed as follows: 

Weigh 3 grams of the finely ground slag, place it :n a 
porcelain casserole, add 25 c.c. of water, and mix thor¬ 
oughly. Add slowly 50 c.c. of hydrochloric acid, and 
warm gently until the slag is disintegrated. If the pre¬ 
liminary test shows that the slag is not soluble in hydro¬ 
chloric acid, proceed as follows: 

Fuse 3 grams of the pulverized slag with about 15 
grams of sodium carbonate and 0.2 gram of sodium ni¬ 
trate in a platinum crucible. Allow to cool, decompose 
the fused mass with hot water in a porcelain casserole, 
and acidify with hydrochloric acid. 

Having gotten the slag in solution or very nearly so, 
add a little nitric acid and evaporate to complete* dryness. 
When the residue is perfectly dry and entirely free from 
acid odors, add 10 c.c. of concentrated hydrochloric acid 
and allow to stand in a warm place for ten minutes. Then 
add water, heat to boiling, filter off the silica and wash it 
with cold water. If the precipitate is not perfectly white, 
but of a brownish color due to the presence of basic fer¬ 
ric salt, pour a few drops of concentrated hydrochloric 
acid around the upper edge of the filter and immediately 
wash again with cold water. 

This separation of the silica is not complete, and in 
order to obtain the silica remaining in the filtrate, evap¬ 
orate it once more to complete dryness in a porcelain 
casserole. Moisten the residue with concentrated hydro¬ 
chloric acid and allow to stand in a warm place for ten 
minutes. Then add water, heat to boiling, and filter off 



METALLURGICAL ANALYSIS 


21 


the remaining silica and wash with cold water, collecting 
the filtrate in a quarter liter graduated flask. 
Place the wet filters containing the silica in a weighed 
platinum crucible, ignite and weigh. Test the purity of 
the silica by adding 4 or 5 drops of water, 2 or 3 drops 
of concentrated sulphuric acid and enough hydrofluoric 
acid to dissolve it. Evaporate to dryness, ignite and 
weigh. Repeat the treatment with the hydrofluoric acid 
until the weight is constant. The loss of weight is silica. 
Calculate the per cent. Si 0 2 . 

The residue left in the crucible is mainly alumina. Cal¬ 
culate per cent and add it to the per cent of Al 2 O a to be 
determined later in the process. 

Dilute the solution in the flask to the containing mark 
and mix thoroughly. 

Determination of the Iron —Take out 50 c.c. of the so¬ 
lution. Reduce the iron with stannous chloride and con¬ 
tinue as directed on page 34. Calculate the per cent, of 
FeO. 

Determination of Phosphorus .— 

To 100 c.c. of the solution add ammonia until in slight 
excess, and then add nitric acid until the precipitate of 
aluminum and iron hydroxides dissolves and the solution 
is slightly acid. Continue with process as directed on 
page 39. 

Determination of Alumina, Manganese, Lime and 
Magnesia —Take 50 c.c. of the solution in a large beaker, 
add sodium carbonate until the fluid is nearly neutral and 
then to the clear liquid add a solution of about five grams 
of sodium or ammonium acetate, dilute to about 500 c.c. 
with boiling distilled water. Heat to boiling for a min¬ 
ute or two, filter while hot and wash by decantation with 


22 


METALLURGICAL ANALYSIS 


hot water containing - a little ammonium acetate or am¬ 
monium nitrate. Dissolve the precipitate in hot dilute 
hydrochloric acid, add a little water, heat to boiling, add 
ammonia in slight excess, filter, and wash with hot water. 
Ignite and wegih Fe 2 0 3 , A 1 2 0 3 and P 2 0 3 . Calculate the 
per cent, of Fe 2 0 3 , A 1 2 0 3 and P 2 0 5 . The per cent, of 
A 1 2 0 3 is determined by subtracting the per cent. Fe 2 O a 
and P 2 O s previously determined from the above. 

Add the filtrate and washings from the acetate precipi¬ 
tation to those from the precipitation by ammonia, evapo¬ 
rate the solution to about 200 c.c. When cold add bro¬ 
mine water until the solution is strongly colored, add 
ammonia in slight excess and heat moderately for some 
time, then filter off precipitate of hydrated peroxide of 
manganese and wash with hot water. Test filtrate with 
more bromine and ammonia, dry, ignite and weigh 
Mn 3 0 4 . Calculate the per cent. MnO. 

Note —The amount of calcium carried down with the 
manganese depends largely upon the relative quantities 
of calcium and manganese. When the amounts of each 
are over 0.02 gram a double precipitation of the manga¬ 
nese should be made. 

When a slag contains a very large amount of manga¬ 
nese instead of precipitating with bromine, add ammonia 
to the solution in slight excess and enough ammonium 
sulphide to precipitate all of the manganese, allow the 
precipitate to settle. Filter the manganese sulphide by 
decantation and wash three times with a 5 per cent 
ammonium nitrate solution containing 1 or 2 c.c. of 
ammonium sulphide, finally transfer the precipitate onto 
the filter paper, dry, ignite the filter paper in a weighed 
porcelain crucible, add the precipitate, heat at first over 


METALLURGICAL ANALYSIS 


23 


a small flame with the crucible cover off, finally increase 
the heat and at last heat over the blast lamp to constant 
weight. Weigh Mn 3 0 4 . Calculate per cent. MnO. In¬ 
stead of weighing the manganese as Mn, 0 4 the sulphide 
may be filtered off and determined as described on 
page 44. 

Acidify the filtrate, from the manganese precipitate, 
with hydrochloric acid and concentrate to about 300 c.c., 
filter if necessary. Add ammonia in slight excess, then 
precipitate the calcium with ammonium oxalate as cal¬ 
cium oxalate, CaC 2 0 4 . Filter, wash, ignite, and weigh 
CaO. Calculate the per cent, of CaO. The precipitate 
of calcium oxalate may be dissolved in dilute sulphuric 
acid and the CaO determined volumetrically by means 
of a standard permanganate solution. See page 18. 

To the filtrate from the calcium oxalate add a volume 
of ammonia of sp. gr. .96 equal to one-sixth the volume 
of the solution. Then add hydrogen sodium phosphate 
drop by drop while stirring the solution with a glass 
rod, to precipitate the magnesium as ammonium magne¬ 
sium phosphate. Allow to stand for some time, filter, 
wash with a mixture of one part of ammonia, sp. gr. .96, 
and three parts water, dry, ignite and weigh Mg 2 P 2 0 7 . 
Calculate the per cent, of MgO. 

Determination of Sulphur.—Take a separate portion, 
using the method described on page 49. Calculate all of 
the sulphur as calcium sulphide (CaS) and the remainder 
of the calcium as calcium oxide (CaO). 


Reference : 


O. Text or, Jour. An. & App. Clietn., Vol. VII, page 257. 


24 


METALLURGICAL ANALYSIS 


METHOD FOR THE COMPLETE ANALYSES OF 
LEAD AND COPPER SLAGS, 

MATTES AND CINDERS. 

To i gram of the pulverized material in a porcelain 
casserole add 25 c.c. of concentrated hydrochloric acid 
and stir with a glass rod until the material is thoroughly 
disseminated through the acid. Heat moderately for 
some time and then add 5 c.c. of concentrated nitric 
acid and heat again for a few minutes. Then add 5 c.c. 
of concentrated sulphuric acid and evaporate until heavy 
white fumes of sulphuric anhydride are evolved. Cool 
and add about 100 c.c. of water. Heat for some time 
and again cool. Filter off the Si 0 2 , BaS 0 4 and PbS 0 4 . 
Wash with dilute sulphuric acid (1 vol. of concentrated 
sulphuric acid to 20 vol. of water) by decantation, leav¬ 
ing as much as possible of the residue in the casserole. 
Set the filtrate aside for the determination of Fe, Al, Cu, 
Zn, Mn, Ca and Mg. 

Boil the residue in the casserole for a short time with 
about 50 c.c. of a solution (200 grams per liter) of 
ammonium acetate, stirring frequently to dissolve the 
lead sulphate. Allow to settle a few moments, then, 
while hot, decant onto the filter used in the first opera¬ 
tion. Boil a second and third time with water containing 
a little ammonium acetate, then by means of hot water 
transfer the residue completely to the filter paper, and 
continue the washing with hot water until the washings 
cease to give a reaction for lead with potassium bichro¬ 
mate. Ignite the residue in a platinum crucible, cool and 
weigh Si 0 2 -{-BaS 0 4 . To the residue in the crucible 
add 3 or 4 drops of dilute sulphuric acid, 1 or 2 c.c. of 




METALLURGICAL ANALYSIS 


25 


hydrofluoric acid and evaporate under the hood to expel 
the silica as SiFl 4 . Ignite and weigh the residue of 
BaSC) 4 . Some kinds of slag which are not easily decom¬ 
posed by acids may leave a residue at this point in the 
process, containing other constituents of the slag than 
barium sulphate. 

To test the purity of the precipitate, mix it in the cru¬ 
cible with five or six times its weight of sodium carbo¬ 
nate and heat to complete fusion. Cool, and extract the 
residue of barium carbonate with hot water. Add hydro¬ 
chloric acid slowly until effervescence ceases, then heat 
to boiling, and add 2 or 3 c.c. of dilute sulphuric acid-. 
Allow the precipitate of barium sulphate to settle, filter, 
wash with hot water, ignite and weigh EaS 0 4 . Add 
the filtrate from the BaS 0 4 to the filtrate which has been 
set aside for the determination of Fe, Al, Cu, Zn, Mn, 
Ca and Mg. 

Determine the lead by either of the following methods: 

(a) To the filtrate containing the lead acetate add 
acetic acid to acid reaction, dilute with water to 250 c.c., 
heat to boiling and titrate with standard ammonium mol¬ 
ybdate solution, using tannin (1 to 300) for indicator. 
See page 12. 

(b) To the filtrate containing the lead acetate add 
sulphuric acid, allow to stand for a short time and filter 
off the lead sulphate. Wash at first with dilute sulphuric 
acid (1 vol. of con. H 2 S 0 4 to 20 vol. water) and then 
with alcohol to displace the sulphuric acid. Dry, ignite 
and weigh the PbS 0 4 in a porcelain crucible. Calculate 
the per cent, of lea^l. 

To the filtrate containing the Cu, Fe, Al, etc., add a 
little hydrochloric acid, heat to about 70 0 and precipitate 


26 


METALLURGICAL ANALYSIS 


the copper as copper sulphide with H 2 S. Filter, wash 
with hydrogen sulphide water, dry, transfer the precipi¬ 
tate to a weighed Rose crucible, burn the filter, add the 
ash to the contents of the crucible. Add a little sulphur, 
ignite in a current of hydrogen or coal gas. Allow the 
crucible and contents to cool in a current of the gas, and 
weigh as Cu 2 S. Calculate per cent, of copper. 

Instead of weighing as Cu 2 S, the precipitate may be 
placed in a beaker, the filter ash added, and the precipi¬ 
tate dissolved in nitric acid, when the copper may be 

determined electrically, colorimetrically or by the volu- 

- • 

metric method. 

Boil the filtrate from the CuS to expel all the hydro¬ 
gen sulphide, filter if necessary, add a little concentrated 
nitric acid and boil for a short time, to oxidize the iron. 
Cool, add sodium carbonate until the solution is nearly 
neutral. Add about 5 grams of sodium or ammonium 
acetate and then about a half liter of hot water, heat to 
boiling and boil for two 01 three minutes. Allow to 
settle for a few moments. Filter while hot and wash 
by decantation with hot water containing a little ammo¬ 
nium acetate or ammonium nitrate. Dissolve the pre¬ 
cipitate in hot dilute hydrochloric acid, add a little 
water, heat to boiling, add ammonia in slight excess, 
filter and wash with hot water. Dissolve this precipi¬ 
tate of iron, alumina (and P 2 0 -) in hydrochloric acid 
and dilute with water to 250 c.c. Take 100 c.c. of the 
250 for volumetric determination of iron. Take another 
100 c.c. and precipitate the iron, aluminum and phos¬ 
phorus with ammonia. Filter, wash and ignite and 
weigh Fe 2 O s , Al 2 O s , P 2 O s . 

Combine the filtrate from the basic acetate precipita- 



METALLURGICAL ANALYSIS 


27 


tion with the filtrate from the first ammonia precipita¬ 
tion, acidify with acetic acid and boil. Conduct into the 
hot solution a current of hydrogen sulphide for half an 
hour. Filter off the precipitate of ZnS and wash with 
water, containing hydrogen sulphide. 

If the precipitate of zinc sulphide is not very large it 
may be dried and ignited in a porcelain crucible, with 
the addition of a little ammonium carbonate to assist 
in the conversion of the zinc sulphide into zinc oxide, 
cooled and weighed as Z11O. 

If the precipitate of zinc sulphide is quite large dis¬ 
solve it in hot dilute hydrochloric acid and precipitate 
the zinc as basic carbonate of zinc with sodium carbo¬ 
nate added in excess and the solution boiled. Filter, 
wash, dry, ignite in a porcelain crucible and weigh as 
zinc oxide. Calculate the per cent, of zinc. 

Boil the filtrate from the precipitate of zinc sulphide 
with an excess of bromine water for about half an hour 
Cool, add ammonia to alkaline reaction and a little more 
bromine water and heat the solution just below boiling 
until the precipitate is brown colored and flaky, and the 
solution colorless. Filter off the precipitated hydrated 
peroxide of manganese, wash thoroughly with hot water, 
test filtrate for manganese with more bromine and am¬ 
monia, heat for some time and filter if necessary, dry, 
ignite and weigh Mn. 5 0 4 . Calculate the per cent, of man¬ 
ganese. 

See also methods for the determination of manganese 
in blast furnace slag, page 21. 

In the filtrate from the manganese determine the cal¬ 
cium and magnesium in the usual manner. 


28 


METALLURGICAL ANALYSIS 


Determination of Sulphur.—Weigh alxxtt i gram of 
the pulverized sample. Mix with it very thoroughly in 
an agate mortar about 2 grams of sodium chloride, 3 
grams of potassium chlorate, and 3 grams of sodium 
carbonate. Transfer the mixture to an iron crucible, 
and heat almost to redness until the bubbling practically 
ceases. Cool, add hot water, and allow to digest for a 
few minutes, filter, and wash with hot water. 

Note .—The sodium chloride is added to moderate the 
action. Carbon dioxide is expelled, potassium chloride 
is formed, and all of the sulphur is converted into so¬ 
dium sulphate. 

To the filtrate containing the sodium sulphate add 
hydrochloric acid in slight excess, heat to boiling, and 
add a hot solution of barium chloride to precipitate the 
sulphur as barium sulphate. Allow to stand a while in 
order to settle, filter, wash with hot water, ignite and 
weigh barium sulphate. Calculate per cent of sulphur. 

COKE AND COAL ANALYSIS. 

Pulverize quickly in an iron mortar 10 to 15 grams of 
the well sampled coal or coke and transfer to a well 
stoppered weighing bottle. 

Determination of moisture — 

Pour from the bottle into the crucible which has been 
cleaned, heated, cooled in a desiccator and weighed to¬ 
gether with the cover, one gram of the sample. Put the 
uncovered crucible into a small beaker, cover the beaker 
and place in a drying oven and keep it at 104° to 107° 
C. for one hour, then remove, cool the crucible in a desic- 




METALLURGICAL ANALYSIS 


29 


cator and weigh covered. The loss in weight represents 
the weight of the moisture. 

As for example :— 

Weight of crucible-)- cover-f-coal=29.1990 grams. 
Weight of crucible-j- cover =28.1990 grams. 

Weight ofcoal = 1.0000 gram. 

Weight of crucible-(-cover-f-coal 

before drying=29.i990 grams. 
Weight of crucible-f-cover+coal 

after drying=29.i8/0 grams. 


Weight of moisture = 0.0120 gram. 

Per cent of moisture=.oi20 by 100 

-=1.20 

1.0000 


Determination of Ash — 

Ignite the residue left in the moisture determination at 
first over a small flame, then with the crucible slightly 
inclined, gradually increase the heat and finally ignite 
until the carbon is all burned. Cool in a desiccator and 
weigh. The difference in weight between the empty cru¬ 
cible and the crucible and ash represents the weight of 
the ash. 

• Weight of crucible-f-cover-|-ash=28.2420 grams. 

Weight of crucible-j-cover =28.1990 grams. 


Weight of ash = 0.0430 gram. 

Per cent of ash=.0430 by 100 

-=4.30 


1.0000 







30 


METALLURGICAL ANALYSIS 


Determination of Volatile Combustible Matter — 

Place one gram of the fresh, undried, pulverized coal 
in a weighed crucible. (Weighed without the cover.) 
Cover the crucible with a tightly fitting cover and heat 
for seven minutes over the full flame of a Bunsen burner. 
Do not uncover the crucible until it is nearly cold, then 
remove the cover, place the crucible in a desiccator, cool 
and weigh. The loss in weight represents the weight of 
the moisture and the volatile combustible matter. To 
find the per cent of voatile combustible matter, subtract 
the per cent of moisture found above from the combined 
per cent of the moisture and volatile combustible matter. 

Weight of crucible-f-Coal=32.2030 grams. 
Weight of crucible =31.2030 grams. 

Weight of coal = 1.0000 gram. 

Per cent of moisture found=i.2 
Weight of crucible-j-coal 

before heating 7 minutes=32.2030 grams. 
Weight of crucible-j-coal 

after heating 7 minutes=31.8330 grams. 

Weight of moisture-f-volatile - 

combustible matter= 0.3700 gram. 

Per cent of moisture-f-volatile combustible matter= 

0.3700 by 100 

-= 37-00 

1.0000 


Per cent of volatile combustible matter=37.00—1.2=35.8 





METALLURGICAL ANALYSIS 


3i 


Determination of Fixed Carbon — 

The per cent of fixed carbon is obtained by subtract¬ 
ing the per cent of ash from the per cent of coke. 
(Coke is the coal residue which remains after excelling 
the moisture and volatile combustible matter.) 

Wt. of crucible-)-coal after heating 7 min.=31.8330 gm. 
Wt. of crucible =31.2030 gm. 

Wt. of coke = 0.6300 gm. 

Per cent of coke=o.6300 by 100 

-=63.00 

1.0000 

Per cent of fixed carbon=63.oo—4.30=58.70 

Determination of Sulphur by Eschka's Method — 

Weigh in a platinum dish of 75 to 100 c.c. capacity 
one gram of finely pulverized coal. Add to this a mix¬ 
ture of one gram of magnesium oxide and one-half gram 
of dry sodium carbonate and mix thoroughly. Place 
the dish on a triangle and heat over an alcohol lamp very 
gently at first with the lamp in the hand. (Illuminating 
gas should not be used on account of the sulphur it con¬ 
tains.) The mixture on first heating is continually 
stirred with either a platinum wire or a glass rod. The 
flame, which at first is kept in motion and barely touch¬ 
ing the dish' until strong glowing ceases, is then so regu¬ 
lated that in fifteen minutes the bottom of the dish is at 
a red heat. When all the carbon is oxidized indicated 
by a cessation of the glow and in most cases by a grey 
color, transfer the ignited mass to a beaker and rinse the 
dish with 50 c.c. ot distilled water, using 10 c.c. portions. 




32 


METALLURGICAL ANALYSIS 


Add 15 c.c. of saturated bromine water, and boil 5 min¬ 
utes. Allow the non-soluble substance to settle and de¬ 
cant the solution through a filter. Boil the residue for 5 
minutes a second and a third time with 30 c.c. portions of 
water, then transfer the residue to the filter and wash re¬ 
peatedly with distilled water until 5 c.c. of the filtrate 
acidified with nitric acid and treated with a few drops of 
silver nitrate gives only a slight opalescence. The filtrate 
should be about 200 c.c. in volume. Add to the filtrate 
one and one-half cubic' centimeters of concentrated hy¬ 
drochloric acid and boil cautiously under the hood until 
the bromine is expelled. Then add to the hot solution, 
drop by drop at first, and with continual stirring 50 c.c. 
of a two per cent solution of hot barium chloride. De¬ 
cant on to a No. 9 filter paper. Then transfer the pre¬ 
cipitate to the filter and wash repeatedly with hot water 
until the filtrate shows the absence of chlorides, transfer 
the filter and precipitate to a weighed porcelain crucible, 
ignite until the residue is white, then cool and weigh the 
barium sulphate (BaS 0 4 ). 

Repeat the igniting (15 minutes) and weighing until 
the weight is constant. Calculate the per cent of sulphur 
as follows: 

Amount of coal taken= 1.0000 gram. 

Weight of crucible-f BaS0 4 =28,2530 grams. 

Weight of crucible =28.1990 grams. 

Weight BaS 0 4 = 0.0540 gram. 

Molecular weight of 

BaS 0 4 : Atomic weight of S : : weight of BaS 0 4 : x 
233 - 1 : 3 2 :: 0.0540 : x 

x=o.oo74 gram, sulphur. 



METALLURGICAL ANALYSIS 


33 


Per cent of sulphur=o.oo74 by ioo 

- 1 -= 0-74 

1.0000 

Note .—For practical purposes the sulphur may be con¬ 
sidered as existing in the coal in the form of pyrites and 
that one-half of it passes off with volatile combustible 
• matter and the other half with the fixed carbon. 

In calculating the results of the analysis one-half of 
the per cent of sulphur may be subtracted from the per 
cent of volatile combustible matter and one-half from 
the per cent of fixed carbon. 

Per cent of volatile combustible matter found=35.8o 
One-half of the per cent of Sulphur = 0.37 

Per cent of volatile combustible matter =35.43 

Per cent of fixed carbon =58.70 
One-half per cent of Sulphur= 0.37 
Per cent of fixed carbon =58.33 

If the calculations are made as here indicated the sum 
total of moisture, ash, volatile combustible matter, fixed 
carbon and sulphur should equal 100 per cent. 

Moisture, 1.20 per cent. 
Volatile combustible matter, 35.43 per cent. 

Fixed carbon, 58.33 per cent. 
Sulphur, .74 per cent. 
Ash, 4.30 per cent. 

I 

100. 

If the determination of phosphorus is desired it may 
be found in the ash after burning the coal or coke and 
can be determined by any of the well-known methods. 

Reference : 

Jour. Am. Chem. Soc., Vol. XXI. page 1116. 

Eschka, Zcit. Anal. Chem., Vol. XIII, page 3. 






34 


METALLURGICAL ANALYSIS 


DETERMINATION OF IRON IN IRON ORES. 

Standardization of Potassium Permanganate Solution : 

Dissolve about eight grams of potassium permanganate 
crystals in about 500 c.c. of water, with frequent agita¬ 
tion to insure complete solution, if possible. After this, 
allow the solution to stand for two or three days. Filter 
through a layer of asbestos, dilute to about 2000 c.c. and 
mix thoroughly. 

Weigh out and place in number 2 beakers two portions 
of standard iron ore of about o .5 gram each. Pour over 
each of these 10 c.c. of hydrochloric acid (sp. gr. 1.2), 
and as much stannous chloride solution as will nearly 
reduce the iron, cover the beakers with glass covers, heat 
at a temperature just below boiling until the undissolved 
residue is white or nearly so. 

The stannous chloride solution should be of such 
strength that about 3.5 c.c. will reduce one-half gram of 
the average iron ore. It may be prepared by dissolving 
pure tin in hot concentrated hydrochloric acid, leaving an 
excess of the acid and then properly diluting with dis¬ 
tilled water, or 

By dissolving 100 grams of stannous chloride salt in 
70 c.c. of concentrated hydrochloric acid and diluting 
with distilled water to one-half liter. 

If a dark residue remains, collect it on a filter, wash 
free from hydrochloric acid, and ignite the filter in a 
platinum crucible. Mix the ash with a small amount of 
sodium carbonate and heat to fusion. Cool and dissolve 
the fused mass in boiling water in the crucible. Unite 
solution and precipitate (if any) with the acid extrac¬ 
tion. Heat the solution then to boiling, wash oft* the 





METALLURGICAL ANALYSIS 


35 


cover and sides of the beaker and add stannous chloride 
solution to the hot solution until it is colorless, but avoid 
adding more than a drop or two in excess. In case a 
larger amount has been added, add permanganate solu¬ 
tion until a tinge of ferric iron is produced. Destroy 
this as above. Dilute with ioo c.c. of water and cool 
completely; when cold add rapidly about 30 c.c. of mer¬ 
curic chloride solution (50 grams per liter). Allow the 
solution to stand 3 minutes, dilute with water to about 
300 c.c. 

Next add about 10 c.c. of a solution prepared as fol¬ 
lows : 160 grams of manganous sulphate dissolved in 

1750 c.c. of water, to which is added 330 c.c. of phos¬ 
phoric acid syrup (sp. gr. 1.7) and 320 c.c. of concen¬ 
trated sulphuric acid. 

Titrate the solution as quickly as possible with the 
potassium permanganate to the appearance of a faint 
pink color, which remains permanent for a short time. 
The reaction for the oxidation of the iron from ferrous 
sulphate to ferric sulphate by the permanganate in pres¬ 
ence of sulphuric acid is as follows: 

ioFeS0 4 +2KMn0 4 +8H 2 S0 4 = 

5 Fe 2 (S 0 4 ) a +K 2 S 0 4 + 2 MnS 0 4 + 8 H 2 0 . 

Calculate the strength of the permanganate in terms 
of metallic iron. 

Standardization of Potassium Bichromate Solution: 

Dissolve about 12 grams of potassium bichromate in 
approximately 2000 c.c. of water. Mix thoroughly and 
standardize by means of standard iron ore. Decompose 
and reduce the ore just the same as in the standardiza¬ 
tion of permanganate solution. Omit the addition of the 


36 


METALLURGICAL ANALYSIS 


manganous sulphate mixture. Titrate the reduced iron 
solution with the potassium bichromate solution. The 
reaction is: 

6FeClo+K 2 Cr 2 0 7 +i4HCl=r6FeCl 3 + 

2 CrCl 3 + 2 KCl+ 7 H 2 0 . 

The end point in the tritation is reached when a drop 
or two of the iron solution and a drop of very weak 
solution of freshly prepared potassium ferricyanide gives 
no blue color when brought together on a porcelain tile. 
Reaction: 

3 FeCl a +2K 3 Fe (CN) 0 =Fe 3 Fe 2 (CN) Ia + 6 KC 1 . 

Calculate the strength of the potassium bichromate 
solution in terms of metallic iron. 

It is advantageous, when one has a great many deter¬ 
minations of iron to make to dilute the standard solution 
so that each c.c. is equivalent to one per cent, or two per 
cent, of metallic iron, when 0.5 gram is taken for analy¬ 
sis. E.g., suppose it is desired to have a permanganate 
solution of such a strength that each c.c. will represent 
1 per cent, of metallic iron when 0.5 gram is taken. 

The calculation is as follows: 
ioFeS0 4 +2KMn0 4 -f8H 2 S0 4 = 

5 Fe 2 (S 0 4 ) 3 +K 2 S 0 4 + 2 MnS 0 4 + 8 H 2 0 . 

ioFe : 2KMn0 4 =.oo5 : x or 
560 : 316 =.005 : x 

x=.oo 28 ii grams KMn 0 4 per c.c. 
.002821 x 1000=2.821 grams of KMn 0 4 per liter. 

Still another practice in commercial work is to weigh 
out the ore in such proportions, that the burette readings 
of the standard solution give the percentage at once with¬ 
out calculation. Thus, if the standard ore contains 64.43 



METALLURGICAL ANALYSIS 


37 


per cent, iron, the weight of ore would be so taken that 
the readings of the burette would be 32.215 c.c. If, 
however, it should be so taken that the reading is 32.8 
c.c., then the weight would be diminished in the propor¬ 
tion of 32.215 to 32.8. For the obtaining of the percent¬ 
age the burette reading is doubled. 

The Process: 

Pulverize the ore in an agate mortar to a fine powder. 
If necessary dry the ore in a drying oven until its weight 
is constant. Weigh out duplicate samples of 0.5 gram 
each. Place each sample in a number 2 beaker and add 
10 c.c. of hydrochloric acid (sp. gr. 1.2) and heat on the 
iron plate. If the ore contains organic matter add a 
little potassium chlorate and boil till the smell of liber¬ 
ated chlorine has disappeared. Add stannous chloride 
and continue as in the standardization of the perman¬ 
ganate solution with standard iron ore. Or, if it is de¬ 
sired to use the bichromate method, continue as in the 
standardization of potassium bichromate with standard 
iron ore. Two results on the same sample should agree 
within 0.1 per cent. 

References : 

R. W. Malion, Am. Ghem. Jour.. Vol. XV, page 360. 

Jour. Am. Ghem. Soc., Vol. XVII, page 405. 

Jour. An. cC App. Chem., Vol. V, page 325. 

DETERMINATION OF PHOSPHORUS IN 

IRON ORES. 

Emmerton's Volumetric Method. — Dissolve 3 
grams of the pulverized ore in 40 c.c. of concentrated 
hydrochloric acid, and evaporate to about 20 c.c., avoid¬ 
ing a temperature so high as to convert the ferric chlo- 


38 


METALLURGICAL ANALYSIS 


ride into ferric oxide. Add io c.c. of concentrated nitric 
acid and evaporate down to about io c.c. If the nitric 
acid solution is allowed to go to dryness, it affords ferric 
oxide, insoluble in nitric acid, which always retains some 
phosphate. This can only be brought into solution by 
hydrochloric acid, which must be removed by addition 
of more nitric acid and evaporating. Dilute with about 
20 c.c. of distilled water and filter into an Erlenmeyer 
flask of about 400 c.c. capacity and wash with the least 
possible amount of water. It is not always possible to 
get the whole of the phosphorus in solution by the above 
process, therefore the residue should be treated by one 
of the following methods in order to obtain any insol¬ 
uble phosphorus which may be present. 

(a) Ignite the residue in a platinum crucible, fuse 
it with 5 to 6 parts of sodium carbonate, dissolve the 
fused mass in water and hvdrochloric acid, evaporate to 
dryness in order to dehydrate any silicic acid that may 
be present. Moisten the residue with concentrated nitric 
acid, heat after adding a small amount of water, and 
filter into the flask containing the soluble phosphorus 
(or into another flask if it is to be determined sepa¬ 
rately) . 

(b) Ignite the residue in a platinum crucible, add 3 
or 4 drops of dilute sulphuric acid and about 5 c.c. of hy¬ 
drofluoric acid, and evaporate under the hood to complete 
dryness and finally ignite to redness. Fuse the residue 
with 5 to 6 parts of sodium carbonate, dissolve the fused 
mass in water and nitric acid and add it to the solution 
in the flask containing the soluble phosphorus. 

(c) Place residue and filter paper in a platinum cru¬ 
cible and ignite. When the paper is burned off break up 


METALLURGICAL ANALYSIS 


39 


the residue with a platinum rod and ignite at a red heat 
for about two minutes. Pulverize the ignited residue in 
an agate mortar. Transfer the residue to beaker, add 
water and a little nitric acid and boil gently for about 5 
minutes. Filter into the flask containing the soluble 
phosphorus. 

To the solution add ammonia, shaking the flask after 
each addition, until the mass sets to a stiff jelly. Then 
add strong nitric acid gradually, shaking well after each 
addition, until the precipitate dissolves and then add a 
little in excess to get a clear amber color. The solution 
at this point should be about 200 to 250 c.c. in bulk. 
Put a thermometer into the liquid and heat carefully until 
the temperature reaches 85° C. Add at once 50 cc. of 
ammonium molybdate solution* to precipitate the phos¬ 
phorus as phosphomolybdate of ammonium, (NH 4 ) 3 P 0 4 , 
12M0O0, 12FFO. Close the flask with a rubber stopper, 
wrap it in a thick cloth or towel and shake or whirl for 
five minutes, then allow to stand for five minutes for the 
precipitate to settle. Filter and wash the precipitate five 
times with water containing 10 c.c. concentrated nitric 
acid per liter and then five times with water, containing 
ten grams of potassium nitrate per liter. Put the funnel 
containing the yellow precipitate in the neck of a flask 
of about 400 c.c. capacity in which has been placed 15 
grams of granulated zinc. 

Pour over the precipitate on the filter dilute ammonia 
(one vol. ammonia, sp. gr. .96, and three volumes of 

♦Ammonium Molybdate Solution.—Mix in a beaker 100 grams of 
pure molybdic anhydride with 400 c.c. of cold distilled water and add 
80 c.c. of ammonia (Sp. gr. 0.9). When solution is complete, filter 
and pour slowly with constant stirring into a mixture of 300 c.c. con¬ 
centrated nitric acid and 700 c.c. distilled water. 



METALLURGICAL ANALYSIS 


P 

water) and receive the solution in the flask containing 
the granulated zinc. Next pour into the flask ioo c.c. 
of dilute sulphuric acid (i vol. acid to 5 vol. of water) 
and heat Qn the iron plate for about 15 minutes. The 
color of the solution passes through pink, plum, pale 
olive green to dark green. The Mo 0 3 is reduced by the 
zinc and sulphuric acid to a mixture of oxides corre¬ 
sponding to the formula Mo 24 0 37 . Filter through a 
folded filter. The zinc is decanted on to the filter paper 
with the liquid to keep up the reducing action. Wash 
two or three times with water. Titrate with standard 
potassium permanganate solution, to the appearance of 
the pink color due to the slight excess of permanganate. 
The reaction is: 

5Mo 24 0 37 +35lCMn 2 0 8 =i2oMo0 3 +35K 2 0+7oMnO. 

The strength of the permanganate solution in terms of 
Mo 0 3 is 88.16 per cent, of its strength against iron. The 
yellow precipitate of phosphomolybdate of ammonium 
contains 12M0CX to 1 of P, the phosphorus being 1,794 
per cent, of the Mo 0 3 . Therefore 88.16% of the 
strength of the solution in terms of iron gives its strength 
in terms of Mo 0 3 and 1.794% of this gives its strength 
in terms of phosphorus. 

Let Fe=the iron value of the permanganate. 

Let P=phosphorus value. 

Then P=Fe X .015816. 

Two results on the same sample should agree within 
.001%. 

It is advisable to check the strength of the standard 
permanganate in terms of phosphorus as calculated above 
by means of a standard iron ore of known phosphorus 
content, or by means of some of the pure yellow precipi- 


METALLURGICAL ANALYSIS 


4T 


tate dried at no°C. It contains 1.63 per cent, phos¬ 
phorus. 


References : 

Emmerton, Trans. Am. Inst. Min. Engs., Vol. XV, page 93. 

Dudley & Pease. Jour. Am. Chem. Soc., Vol. XVI, page 224. 

Blair & Whitfield, Jour. Am. Chem. Hoc.. Vol. XVII, page 747. 

G. Auchy, Jour. Am. Chem. Soc., Vol. XVIII, page 955. 

W. A. Noyes, Jour. Am. Chem. Soc., Vol. XVI, page 553. 

W. A. Noyes, Jour. Am. Chem. Soc., Vol. XVII, page 129. 

Mixter & Du Bois, Jour. Am. Chem. Soc., Vol. XIX, page 614. 

II. C. Babbitt, Jour. Am. Chem. Soc., Vol. VII, page 165. 

E. D. Campbell, Jour. Am. Chem. Soc., Vol. VII, page 2. 

Dudley & Pease, Jour. Am. Chem. Soc., Vol. VII, page 519. 

P. W, Shimer, Jour. Am. Chem. Soc., Vol. XXI, page 723. 

J. E. Stead, Chem. Eng., Vol. II, No. 1, page 18 . 

Reduction of the MoO z in a Redactor : 

Obtain the yellow precipitate and dissolve it in am¬ 
monia just as described on page 39 and the solution is 
allowed to run into a clean beaker. Wash the filter 
paper with water until the solution measures about 60-70 
c.c. Add to the liquid in the beaker 10 c.c. concentrated 
sulphuric acid and pass, it through the reductor which 
has just been cleaned by passing through it distilled 
water and then 100 c.c. of warm dilute sulphuric acid, 
strength: 25 c.c. concentrated sulphuric acid per liter of 
distilled water. After passing the molybdate solution 
through the reductor, wash with about 200 c.c. of the 
warm dilute sulphuric acid, and finally with about 50 c.c. 
hot water. 

References : 

Jones’ Reductor, Trans. Am. Inst. Min. Engs. Vol. XVII, page 441. 

Dudley & Pease, Jour. An. <(• App. Chem., Vol. VII, page 109. 

Acidimetric Method .—Follow Emmerton’s method un¬ 
til the yellow precipitate of ammonia-phospho-molybdate 
is obtained and then continue as follows: Filter the yel¬ 
low precipitate on a 9 c.m. filter and wash by decanta¬ 
tion with water containing 10 c.c. concentrated nitric acid 


42 


METALLURGICAL ANALYSIS 


per liter and then five times with water containing io 
grams potassium nitrate per liter. Place precipitate and 
filter in the flask containing the bulk of the precipitate. 
Dissolve the precipitate in an excess of standard solu¬ 
tion of caustic soda or caustic potash. With potash the 
reaction is: 

2 (NHJ 3 P 0 4 , 24M0O3+46KOH+ H 2 0 = 

( NH 4 ) 4 H 2 P 2 O s + (NH 4 ) 2 Mo0 4 +23K 2 Mo0 4 +2 3 H 2 0. 

Add water and a few drops (.5 c.c.) of phenol-phthalein 
indicator and titrate the excess of caustic alkali with a 
standard solution of nitric acid. 

Solutions Required: 

Standard Caustic Potash .—Strength, 8.3334 grams of 
potassium hydroxide per liter. This solution may be 
prepared from normal caustic potash solution by taking 
148.39 c.c. and diluting to one liter with distilled water. 
One cubic centimeter of this solution will equal .0002 
gram of phosphorus. 

Standard Caustic Soda. —Strength, 5.9355 grams of 
sodium hydroxide per liter. This solution can be pre¬ 
pared from normal caustic soda by diluting 148.39 c.c. 
to one liter. This solution is of such a strength that one 
c.c. equals .0002 gram phosphorus. 

Standard Nitric Acid. —This solution has the same 
strength, volume for volume, as the caustic soda or caus¬ 
tic potash. It can be prepared by diluting 148.39 c.c. of 
normal nitric acid to one liter. It contains 9.3484 grams 
of nitric acid to the liter. 

Phenol-phthalein. —One gram dissolved in 100 c.c. of 
60% alcohol. 


METALLURGICAL ANALYSIS 


43 


Calculation of Analysis .—The difference between the 
number of c.c. of caustic alkali used and the number of 
c.c. of standard acid multiplied by .0002 gives the weight 
of phosphorus found. 

Weight of Phosphorus X 100 

-= per cent, phosphorus. 

Amount of ore taken 

It is advisable to check the strength of the standard 
acid and alkali in terms of phosphorus as calculated 
above, against a standard iron ore of known phopshorus 
content, or by means of some of the pure yellow pre¬ 
cipitate dried at iio°C. It contains 1.63 per cent, phos¬ 
phorus. 

References : 

.T. O. Handy, Jour. An. cC- App. Chem., Vol. VI. page 204. 

Manby, Jour. An. d App. Chem., Vol. VI. page 82. 

M. Rothberg, Jour. An. <6 App. Chem., Vol. VI, page 241. 

F. Ilundesliagen, Zeit. Anal. Chem., Vol. XXV, page 489. 

Wood's Method .—Direct weighing of the phosphomo- 
lybdate of ammonium. 

Follow Emmertoirs method until the yellow precipi¬ 
tate is obtained then filter on a 9 c.m. filter which has 
been previously dried at iio°C. and weighed. Wash 
with a two per cent, nitric acid solution until free from 
iron, then wash once or twice with alcohol. Dry in the 
air bath at no°C. and weigh. 1.63 per cent, of the dried 
precipitate is phosphorus. 

A Ate .—The yellow precipitate must contain no silica. 
With ores containing soluble silicates, evaporate the acid 
solution to complete dryness, to render the silica insol¬ 
uble, moisten with hydrochloric acid, add water, heat, 
and filter off the insoluble residue. 

Reference : 

E. F. Wood, Zeit, Anal. Chem., Vol. XXVIII, page 141-172. 



44 


M ETALLURGICAL ANALYSIS 


DETERMINATION OF MANGANESE IN 

IRON ORES. 

Volhard’s Method, modified by G. C. Stone. —Grind 
the ore to a fine powder. Weigh out two portions of 
about one gram each and place in number 2 beakers. 
Pour into each 10 c.c. of concentrated hydrochloric acid. 
Cover the beakers with glass covers and heat until ore 
is decomposed. Add a little potassium chlorate and boil 
a minute or two. Remove covers and evaporate oft* ex¬ 
cess of acid. Cool and add cold water. At this point if 
there is any doubt as to the decomposition of the ore, 
filter off and test insoluble residue for manganese. If 
not, the filtration may be omitted. Wash contents of the 
beaker into a half liter flask with cold water. Nearly 
neutralize with carbonate of soda; the solution should 
remain clear and should be of a deep red color. Next 
add an emulsion of zinc oxide until the precipitate curdles 
and settles readily. Add a little more of the emulsion 
to make sure that the precipitation is complete. The 
reaction is: 

2FeCl 3 +3ZnO+3H 2 C=2Fe(OH) 3 -|-3ZnCl 2 . 

Dilute to the mark with cold water, mix thoroughly,, 
pour into a beaker and allow the precipitate to settle. 
Take portions of 200 c.c. each of the supernatant liquid 
and transfer to 400-500 c.c. flasks; heat nearly to boiling 
and titrate one after the other with standard potassium 
permanganate solution, adding it in small portions at a 
time, and shaking the flask over a Bunsen flame, after 
each addition. Keep the temperature as near the boiling 
point as possible, while making the titration. The greater 
part of the permanganate solution should be added at 


METALLURGICAL ANALYSIS 


45 


once and the solution vigorously shaken and then the 
precipitate allowed to settle. The following is the reac¬ 
tion which takes place: 

4KMn0 4 +6MnCl 2 +4H 2 0=ioMn0 2 +4KCl+8HCL 
In the above equation we see that two molecules of potas¬ 
sium permanganate oxidizes three molecules of manga¬ 
nous chloride, while in the following equation: 

2KMn0 4 + ioFeS 0 4 + 8 H 2 S 0 4 = 

5Fe 2 (S0 4 ) 3 +K 2 S0 4 +2MnS0 4 +8H 2 0 
we see that two molecules of potassium permanganate 
oxydizes ten molecules of ferrous sulphate, therefore the 
oxydizing power of KMn 0 4 in the former case is only 
3 /io as great as in the latter. So the value of the per- 
manganate in terms of manganese is to its value in terms 
of iron as 3:10 or 55 / 56 X 3 / 10 = 165 / 560 . The value of 
the standard permanganate solution in terms of iron 
multiplied by 1G5 / 5C0 gives strength of permanganate so¬ 
lution in terms of manganese. 


References : 

Ann. der Cliem. and Pliarm., 11KS, page 318. 

Jour. Am. Chem. 80 c., Vol. XVIII, page 385. 

Licbeg's Annalen, 197, page 318. 

Chem. News, Vol. XL, page 207. 

G. C. Stone, Jour. Am. Chem. 80 c., Vol. XVIII, page 228. 

G. Auchy, Jour. Am. Chem. ■ 8 oc., Vol. XVIII, page 498. 

Ford-Williams Method.— This is a good method to 
use when the ore contains only a small amount of man¬ 
ganese. 

Pulverize the ore to a fine powder. Weigh out dupli¬ 
cate samples of one to five grams each. With ores high 
in manganese use one gram; with ores low in manganese 
weigh about five grams. Place each sample in a number 
4 beaker, add 10 c.c. concentrated hydrochloric acid for 


46 


METALLURGICAL ANALYSIS 


each gram of ore taken. Cover the beaker ancl heat on 
the iron plate until the residue is white or nearly so. 
Then add 25 to 50 c.c. strong nitric acid and boil about 
five minutes to expel hydrochloric acid. If there is a 
large insoluble residue, filter it on an asbestos filter and 
wash with strong nitric acid. ' If the insoluble residue 
is small, the filtration may be omitted. 

Now add 75 c.c. of strong nitric acid and heat. When 
the solution is warm add about 5 grams of potassium 
chlorate, bring the solution to a boil and continue the 
boiling about 10 minutes. If the sample contains much 
silica, add a few drops of hydrofluoric acid (more or 
less according to the amount of silica present) and boil 
for a few minutes. Allow it to cool somewhat, add 25 
c.c. more nitric acid and five grams more of potassium 
chlorate and again boil for about 10 minutes. If the 
nitric acid has the faintest yellow color, it indicates the 
presence of nitrous acid. Nitrous acid reduces MnO s to 
MnO, which is soluble. This acid may be removed by 
blowing a current of air through the HNO a . 

Manganous nitrate in the strong nitric acid solufion 
is, by a complex reaction, oxidized to insoluble manga - 
nese dioxide on the addition of potassium chlorate. The 
following is probably the reaction : 

2Mn0+N 2 0 5 =2Mn0 2 +N 2 0 3 . 

N 2 0 3 +Cl‘ 2 0 5 =N 2 0 5 +Cl 2 6 3 . 

Cool the solution quickly and filter on an asbestos filter, 
using a filter pump. Wash two or three times with 
strong nitric acid, suck the precipitate as dry as possible 
and then wash two or three times with cold water to get 
rid of all the nitric acid. Transfer the precipitate with 
the asbestos filter to the beaker in which the precipitation 


METALLURGICAL ANALYSIS 


47 


was made. Measure into the beaker ioo c.c. of a stand¬ 
ard solution of ferrous sulphate prepared as follows: 

io grams of crystalized salt, FeS 0 4 , /H 2 0 in 900 c.e. 

water and' 100 c.c. Con. H 2 S 0 4 , thoroughly mixed. 
The reaction between the precipitate of Mn 0 2 and this 
solution is: 

Mn 0 2 -f 2FeS0 4 -f2H 2 S0 4 = 

MnS 0 4 +Fe 2 (S 0 4 ) 8 +2lLO. 
Stir until the whole of the precipitate has been dis¬ 
solved. Dilute the solution with water and titrate the 
excess of ferrous sulphate with a standard potassium 
permanganate solution. If the strength of the perman¬ 
ganate solution in terms of iron is known, its strength 
in terms of manganese can be calculated from the above 
reaction. We see that two Fe is equivalent to one Mn 
and we can make the following proportion: 

112:515Strength of permanganate in terms of Fe : x 

x=Strength of permanganate in terms of Mn. 

Find the value of the ferrous sulphate solution in 
terms of the permanganate solution by taking 50 c.c. of 
the ferrous sulphate solution, placing it in a beaker, 
adding water and titrating to a faint pink color with per¬ 
manganate. 

Example: 

Amount of ore taken for analysis, 2 grams. 

Strength of the permanganate in terms of Mn, .G02 
gram. 

50 c.c. Ferrous Sulphate solutions 15 c.c. Permanga¬ 
nate. Then 100 c.c. Ferrous Sulphate solution=30 c.c. 
permanganate. After treating the precipitate of MnO, 
with 100 c.c. of ferrous sulphate solution it required 10 


METALLURGICAL ANALYSIS 


48 


c.c. of the standard permanganate solution to give a per¬ 
manent pink color. As 100 c.c. of the ferrous sulphate 
solution=30 c.c. of the permanganate solution, there 
would be the equivalent of 30—10 c.c. or 20 c.c. of per¬ 
manganate in ferrous sulphate oxydized by the Mn 0 2 . 

One c.c. of the permanganate being equal to .002 gram 
of manganese, 20 c.c. is equal to .04 gram Mn, and 2 
grams of the sample having been taken. 

.04X100 

- —2 per cent, manganese. 

2 

References : 

Ford, Jour. Am. Chew. Soc., Vol. XX, page^ 504. 

Ford, Trans. Am. Inst. Min. Enys., Vol. IX, page 307. 

Julian's modification of the above methods is as fol¬ 
lows : Obtain the manganese dioxide precipitate exactly 
as given above; when the manganese is all oxidized to 
dioxide, cool, and dilute to 400-450 c.c. Now add from a 
burette an excess of standard hydrogen peroxide, to 
completely dissolve the precipitate. The reaction is: 

Mn0 2 -f-H 2 0 2 +H 2 S0 4 =MnS0 4 -}-2H 2 0-|-0 2 . 
Immediately titrate the excess of hydrogen peroxide with 
a standard potassium permanganate solution. The reac¬ 
tion is: 

2KMn0 4 +5H 2 0 2 +4H 2 S0 4 = 

2HKS0 4 +2MnS0 4 +8H 2 0+5(X. 

The hydrogen peroxide solution is prepared by thor¬ 
oughly mixing 30 c.c. of hydrogen peroxide with about 
JX liter of water and 10 c.c. of concentrated sulphuric 
acid. It is standardized by means of standard potas¬ 
sium permanganate solution. 

References : 

F. Julian, Jour. Am. Chem. Soc., Vol. VII. page 113. 

F. Julian, Berg. u. Huttenmann, Zcit., 1897, pages 5G, 410. 

Jour. Soc. Chcm. Industry, 1898, page 185. 



METALLURGICAL ANALYSIS 


49 


» 

DETERMINATION OF SULPHUR IN IRON 

ORES. 

Weigh one gram of the finely pulverized ore into a 
large platinum crucible; add about eight grams of chem¬ 
ically pure carbonate of soda and about one-half gram of 
potassium nitrate; mix thoroughly and heat carefully un¬ 
til the mass appears liquid and in a quiet state of fusion. 
Cool and treat with hot water until the fused mass is 
decomposed. If the solution is red or green it indicates 
the presence of manganese; add a few drops of alcohol, 
which will precipitate the manganese as manganese diox¬ 
ide. Filter and wash with hot water. Acidulate the 
filtrate with hydrochloric acid and evaporate to complete 
dryness. Treat the residue with water and a few drops 
of hydrochloric acid, heat and filter. Wash with hot 
water; heat the filtrate to boiling and precipitate the sul¬ 
phur with a hot solution of barium chloride. Allow the 
precipitate to settle, filter, wash with hot water, ignite 
and weigh as barium sulphate. Calculate the per cent, of 
sulphur in the ore. 

Aqua Regia Method .—Weigh out from one to five 
grams of the finely pulverized ore. If high in sulphur, 
one gram; if low in sulphur, five grams. Place in a 
beaker and add about 20 c.c. of aqua regia for every 
gram of ore taken. Cover the beaker and warm for some 
time, then remove cover and evaporate to dryness. 
Allow to cool. Moisten the residue with hydrochloric 
acid ; add water, heat, and filter. Dilute the filtrate to 
about 200 c.c.; heat to boiling; add solution of barium 
chloride to precipitate the sulphur as barium sulphate. 
Allow the precipitate to settle, filter, wash with hot water, 
ignite and weigh. Calculate per cent, of sulphur in the 


ore. 


50 


METALLURGICAL ANALYSIS 


DETERMINTION OF SILICA IN IRON ORES. 

Method I .—Dissolve one gram of the pulverized ore 
in hydrochloric acid; evaporate to dryness. Moisten the 
residue with concentrated hydrochloric acid; add water, 
heat, filter, wash and ignite and weigh the insoluble resi¬ 
due in a platinum crucible. Treat the residue with 
hydrofluoric acid and a few drops of sulphuric acid; 
evaporate to dryness; ignite and weigh. In almost all 
iron ores the loss in weight would represent the silica. 
If, however, the insoluble residue contains calcium, mag¬ 
nesium, sodium, or potassium, the loss in weight would 
not represent the silica, but should be increased by the 
amount of So 3 found in the insoluble residue in combina¬ 
tion with these elements. 

To determine the SO s , fuse the residue with a little 
carbonate of soda, dissolve in hot water, acidulate with 
hydrochloric acid, heat to boiling, and add a solution of 
barium chloride. Filter off the precipitate, ignite and 
weigh as barium sulphate. Calculate the amount of 
S 0 3 and add its weight to the loss by volatilization with 
the hydrofluoric acid. 

Method II .—Weigh one gram of the ore into a platin¬ 
um crucible, and mix with about eight times its weight 
of carbonate of soda; fuse thoroughly; dissolve the fused 
mass in hot water; aciduate with hydrochloric acid; 
evaporate to dryness in a casserole; moisten the residue 
with concentrated hydrochloric acid and allow to stand 
in a warm place for about ten minutes. Then add water, 
heat to boiling, filter, and wash alternately with dilute 
hydrochloric acid and cold water. Evaporate the filtrate 
to complete dryness in a porcelain casserole, moisten the 


METALLURGICAL ANALYSIS 


5i 


residue with concentrated hydrochloric acid and allow to 
stand in a warm place for a few minutes. Then add 
water, heat to boiling, filter off the remaining silica, and 
wash it alternately with dilute hydrochloric acid and cold 
water. Ignite the wet filters containing the silica, cool, 
and weigh. 

If greater accurcy is desired the silica may be treated 
with hydrofluoric acid and sulphuric acid ; the loss after 
evaporation and ignition is weight of silica. 

The filtrate from the silica may be used for the deter¬ 
mination of alumina. 

Method III .—Treat about one gram of the ore in a 
number two beaker with 20 c.c of concentrated hydro¬ 
chloric acid. Cover the beaker and heat until the ore 
is decomposed. Remove the cover and evaporate to dry¬ 
ness. Moisten the residue with concentrated hydrochlor¬ 
ic acid, add water, heat and filter. Wash with water, 
ignite the residue in a platinum crucible, and fuse with 
eight parts of sodium carbonate. Cool; treat the fused 
mass with dilute hydrochloric acid, evaporate to dryness. 
Moisten the residue with concentrated hydrochloric acid 
and allow to stand in a warm place for about ten min¬ 
utes. Then add water, heat to boiling, filter and wash 
alternately with dilute hydrochloric acid and cold water. 
Evaporate the filtrate to complete dryness in a porcelain 
casserole, moisten the residue with concentrated hydro¬ 
chloric acid and allow to stand in a warm place for a 
few minutes. Then add water, heat to boiling, filter off 
the remaining silica, and wash it alternately with dilute 
hydrochloric acid and cold water. Ignite the wet filters 
containing the silica, cool, and weigh. 


5 2 


METALLURGICAL ANALYSIS 


The combined filtrates from the silica may be used 
for the determination of alumina. 

Reference: 

W. F. Ilellebrand, Jour. Am. Chem. Soc., Yol. XXIV, page 435. 

DETERMINATION OF ALUMINA IN IRON 

ORES. 

About i. gram of the finely pulverized ore is dissolved 
in 15 c.c. of concentrated hydrochloric acid, the siliceous 
residue filtered off and ignited in a platinum crucible and 
the silica volatilized as silicon tetrafluoride, SiFl 4 ; with 
hydrofluoric acid. The residue from the silica is then 
fused with anhydrous sodium carbonate, and the fusion 
decomposed with water and hydrochloric acid, and add¬ 
ed to the original filtrate. A solution of hydrogen so¬ 
dium phosphate, somewhat in excess of the required 
amount to precipitate the aluminum is then added (about 
20 c.c. of a 10% solution). 

The solution is neutralized with ammonia water using 
a drop or two of methyl orange for the indicator and 
then just sufficient hydrochloric acid is added to dissolve 
the precipitated phosphate. It should require about 3.5 
c.c. of the concentrated hydrochloric acid. A solution 
of sodium thiosulphate sufficient to neutralize the acid is 
then added. This will require about 15 grams of the 
thiosulphate which should be dissolved in about 75 c.c. 
of distilled water before being added. Sulphur is pre¬ 
cipitated and the iron reduced to the ferrous state. The 
solution is next diluted with water to 400 or 500 c.c., 
heated to boiling, 15 c.c. of acetic acid (sp. gr. 1.04) 
added, and boiled for about one-half hour, or until SO, 


METALLURGICAL ANALYSIS 


53 


is expelled. The precipitate is filtered, washed, ignited 
in a porcelain crucible and weighed as A 1 P 0 4 . Calculate 
per cent. A 1 2 0 3 . 

DETERMINATION OF TITANIUM IN IRON 

ORES. 

One gram of the finely pulverized ore intimately 
mixed in a large platinum crucible with 12 grams of pot¬ 
assium di-sulphate and 2 grams of sodium fluoride is 
gradually heated by a low flame until the di-sulphate is 
melted. Heating is continued, keeping the mass just 
liquid and the temperature at the point at which slight 
fumes of sulphuric anhydride are given off when the lid 
of the crucible is raised, until all the particles of the ore 
have disappeared. Remove the flame', and, as the melt 
cools, incline the crucible in different directions, so that 
the fused mass may solidify well up on the sides. 
When cool add 2 or 3 c.c. concentrated sulphuric acid, 
and carefully heat until the mass is just liciuid. Discon¬ 
tinue heating, and place a platinum rod in the solidifying 
melt. When cold, fuse the mass where it is in contact 
with the crucible, and remove it by means of the platin¬ 
um rod to a beaker containing 150-200 c.c. of a 5 per 
cent, solution of sulphuric acid. In the beaker also place 
the crucible and cover. Gently warm, but do not raise 
the temperature of the beaker and its contents beyond 
that which can be comfortably endured by the palm of 
the hand. The melt should completely dissolve to a clear 
solution. Determine the titanium in the solution by one 
of the following methods. 

Gooch's Method .—Add ammonia carefully until the 
precipitate which first forms dissolves with difficulty 


54 


METALLURGICAL ANALYSIS 


upon stirring. If too much ammonia has been added, and 
the precipitate does not redissolve, a few drops of hydro¬ 
chloric acid may be used for the purpose. Next add 
about 50 c.c. of sulphurous acid or 5 c.c. of ammonium 
bisulphite and heat nearly to boiling until the iron is 
completely reduced. The solution should not be heated 
to boiling or the Ti 0 2 Will be precipitated as a white 
milky precipitate which will render it difficult to deter¬ 
mine when the iron is completely reduced. Add 10 c.c. 
of sulphurous acid, 20 grams of sodium acetate (in solu¬ 
tion), and one-sixth the total volume of acetic acid (sp. 
gr. 1.04). The solution is heated to boiling, the titanium 
. being precipitated in a flocculent condition. Boiling is 
continued for two or three minutes. If filtered immedi¬ 
ately, the filtrate, upon evaporation, is sometimes found 
to contain traces of titanic acid; this, however, may be 
obviated by digesting the previously boiled precipitate on 
the steam bath for half an hour. 

After allowing the precipitated titanic acid to settle, 
filter, wash with hot water containing 5 per cent, of ac¬ 
etic acid, and finally with hot water. The titanic acid 
precipitate is generally contaminated more or less with 
iron, alkali sulphates, alumina, phosphoric acid, etc. In 
order to eliminate these impurities, the precipitate is 
thoroughly ignited in a platinum crucible to burn out the 
carbon of the filter paper, and then fused thoroughly 
with sodium carbonate (avoid presence of potassium car¬ 
bonate) and 0.2 to 0.3 gram sodium nitrate, in order to 
form soluble phosphate and aluminate of sodium; the 
titanium, at the same time is converted into insoluble 
sodium titanate, and the iron into insoluble ferric oxide. 
A liberal amount of the flux and an hour’s fusion with the 


METALLURGICAL ANALYSIS 


55 


strong flame of a blast lamp are necessary to effect these 
changes completely. After fusion, the melt is boiled 
with a solution of sodium carbonate, filtered and washed 
with water containing a little sodium carbonate. The 
insoluble sodium titanate and ferric oxide are collected 
on a filter, dried in an air-bath, and transferred to a plat¬ 
inum crucible. The filter paper is burned, on a 
platinum wire, and the residue also added to the 
crucible. The contents of the crucible are fused with 
a little sodium carbonate, and the cooled mass treat¬ 
ed in the crucible with sulphuric acid, heat being grad¬ 
ually applied until fumes of sulphuric anhydride are 
evolved. After cooling, the liquid or pasty mass is dis¬ 
solved in a mixture of ioo c.c. of water and 20 c.c. sul¬ 
phurous acid. Then, after nearly neutralizing with am¬ 
monia until the precipitated titanic acid dissolves with 
difficulty, 5 to 10 grams of sodium acetate (in solution) 
and 25 c.c. of acetic acid (sp. gr. 1.04) a,re added. The 
solution is boiled for several minutes; digested on the 
steam bath for half an hour at a temperature just below 
boiling; the precipitated titanic hydrate filtered; washed 
with hot water containing 5 per cent, of acetic acid, and 
finally with hot water; ignited and weighed as titanic ox¬ 
ide (TiOo). 

Betters Method —To the solution add sodium carbon¬ 
ate so long as it can be added without forming a per¬ 
manent precipitate. Then add 3 c.c. of dilute sulphuric 
acid and 100 or 150 c.c. of a strong solution of sulphur¬ 
ous acid; dilute with cold water to about 700 c.c. Cover 
with a watch glass and slowly heat to boiling. Continue 
the boiling for about two hours. Add hot water and a 
little sulphurous acid from time to time during the boil- 


56 


METALLURGICAL ANALYSIS 


ing so as to keep the bulk of the solution to about 700 c.c. 
During the boiling, sulphur dioxide should always be 
present to keep the iron reduced to the ferrous form, oth¬ 
erwise more or less iron would be precipitated along with 
the titanium dioxide. Allow the precipitate to settle. 
(Do not use filter pump.) Filter, wash with water con¬ 
taining a little sulphurous acid and a little ammonium 
sulphate. Dry, ignite in a platinum crucible, partly cool, 
add a few pieces of solid ammonium carbonate and again 
ignite to remove traces of sulphuric anhydride. Cool 
and weigh as Ti 0 2 . 

This may contain traces of iron oxide, calcium sul¬ 
phate or phosphoric acid, therefore if very accurate re¬ 
sults are desired, weigh into the crucible six or eight 
parts of carbonate of soda and mix it with the Ti 0 2 and 
fuse thoroughly. Cool, dissolve the fused mass in hot 
water, filter and wash with hot water. Ignite the pre¬ 
cipitate of titanate of soda (Na 2 0 . Ti 0 2 ) in a platinum 
crucible and fuse it with about fifteen times its weight of 
potassium bisulphate, observing the same precautions as 
in first fusion. Cool, place in a beaker, add cold water. 
When decomposed, filter, if necessary and wash with 
cold water. Determine the titanium in the filtrate by 
either of the following methods: 

(a) Dilute and precipitate titanium di-oxide by boiling 
in presence of sulphurous acid. Filter, ignite and weigh 
Ti 0 2 . 

(b) To the solution add about 20 c.c. sulphurous acid, 
and about 10 grams of sodium acetate and 40 c.c. of acet¬ 
ic acid, heat to boiling for about 15 minutes. Allow the 
precipitate to settle, filter, wash with hot water contain¬ 
ing a little acetic acid, dry, ignite and weigh TiQ 2 . 


METALLURGICAL ANALYSIS 


57 


Weller's Color Method. 

Dilute the solution to 500 c.c. with 5 per cent, sul¬ 
phuric acid and mix thoroughly. Put 50 c.c. of the so¬ 
lution into a comparison tube. Put into a second com¬ 
parison tube as much of a standard ferric sulphate solu¬ 
tion, containing 5 per cent, sulphuric acid, as will contain 
an amount of iron equal to that in 0.1 gram of the ore 
and dilute to 50 c.c. with 5 per cent, sulphuric acid. 

Add to each tube 5 c.c. of hydrogen peroxide and then 
add to the second tube from a burette a standard solu¬ 
tion of titanium sulphate until the yellow color produced 
matches that in the first tube. From the volume of the 
standard solution used calculate the per cent, of Ti 0 2 in 
the ore. 

To prepare the standard titanium sulphate solution 
either of the following methods may be used: 

Method I. Take 0.6 gram of potassium titanium flu¬ 
oride, which corresponds to 0.2 gram of Ti 0 2 , and heat 
in a platinum crucible with a little water and about 1 c.c. 
of concentrated sulphuric acid and expel the excess of 
acid by gentle ignition. Repeat several times, then add 
a little concentrated sulphuric acid, and water, and heat 
to obtain solution. Then dilute with 5 per cent, sulphuric 
acid to 100 c.c. and mix thoroughly. 1 c.c.=.002 gram 
Ti 0 2 . 

Method II. 

Fuse 0.5 gram of pure Ti 0 2 in a platinum crucible 
with 5 grams of potassium bisulphate. Cool and dissolve 
the fusion in 5 per cent, sulphuric acid. Dilute the so- 
tion to 500 c.c. with the 5 per cent. acid. 

This method is very satisfactory for the de¬ 
termination of titanium in ores containing less than 


53 


METALLURGICAL ANALYSIS 


about 4 per cent. For ores containing more than 4 per 
cent, the Gooch method is recommended. 


References : 

Gooch. Proc. Am. Acad. Arts and Sciences, New Series, Vol. XII. 
page 435. 

A. A. Blair, The Chemical Analysis of Iron. 

F. .7. I’ope, Trans. Am. Inst. Min. Engs., Vol. XXIX, page 372. 

.T. O. Arnold, Steel Works Analysis. 

H. L. Wells and W. L. Mitchell, Jour. Am. Cliem. Soc., Vol. 
XVII, page 878. 

W. Bettel. See Crooke's Select Methods, page 194. 

.7. W. Bain, Jour. Am. Client. Soc., Vol. XXV. page 1073. 

Weller, Her. d. Cliem. Gcs., Vol. XV., page 2593. 


DETERMINATION OF MOISTURE IN IRON 

ORES. 

Weigh out one or two grams of ore in a bulb tube and 
ignite in a slow current of dry air. Collect the water in 
a weighed calcium chloride tube which is connected with 
the bulb ignition tube. The increase in weight of the 
calcium chloride tube gives the amount of moisture in 
the sample. Calculate the per cent. 


DETERMINATION OF CARBONIC ACID IN IRON 

ORES. 

Take for this determination from one to five grams of 
the pulverized ore, the amount taken depending upon the 
amount of carbonic acid expected. Decompose the car¬ 
bonate in a flask which is connected with a weighed caus¬ 
tic potash absorption bulb. The increase in weight of 
the absorption bulb gives the weight of carbon dioxide 
in the sample. 

DETERMINATION OF FERROUS IRON IN IRON 

ORES. 

Weigh into a large platinum crucible one gram of the 


METALLURGICAL ANALYSIS 


59 


finely pulverized ore and heat on a water bath with about 
20 c.c. concentrated hydrochloric acid and about 20 c.c. 
of hydrofluoric acid. A water bath constructed for this 
process is provided with a grooved ring in which a fun¬ 
nel stands. A little water placed in the groove forms a 
tight joint. It is also provided with a tube in the side 
through which carbon dioxide can be passed to exclude 
the air during the process, and thus prevent any oxida¬ 
tion of the ferrous iron. Stir the contents of the crucible 
from time to time with a long platinum wire. When the 
ore is dissolved transfer the contents of the crucible to 
a beaker. Add water and determine the ferrous iron 
present by means of a standard solution of potassium 
bichromate. Calculate the per cent, of FeO. 

COMPLETE ANALYSIS OF IRON ORES 

(Method suitable for all iron ores excepting those con¬ 
taining considerable titanic acid.) 

Treat five grams of the finely ground ore in a number 
three beaker with about 50 c.c. strong hydrochloric acid 
and one or two c.c. strong nitric acid. Heat the mixture 
until the ore is decomposed. Evaporate to dryness in 
order to render insoluble any silica which may have been 
dissolved. Moisten the residue with concentrated hydro¬ 
chloric acid, add water, heat, filter into a 250 c.c. flask. 
Wash with water, ignite the siliceous residue in a plati¬ 
num crucible and fuse it with about eight times its weight 
of carbonate of soda. Decompose the fused mass with 
water acidify with hydrochloric acid, evaporate to dryness ; 
heat in a drying oven for an hour at iio° to I20°C. 
Cool, moisten with concentrated hydrochloric acid, add 


6 o 


METALLURGICAL ANALYSIS 


water, heat, filter into the 250 c.c. flask containing the 
first filtrate. Wash with cold water, ignite and weigh 
the SiO s . Dilute the solution in the flask to the contain¬ 
ing mark and mix thoroughly. 

Determination of the Iron .—Take out 50 c.c. of the so- 
tion. Reduce the iron with stannous chloride and con¬ 
tinue as directed on page 34. Calculate the per cent, of 
Fe 2 O a . 

Determination of the Phosphorus. —To 100 c.c. of the 
solution add ammonia until the mass sets to a stiff jelly, 
making sure that there is present an excess of ammonia. 
Next add strong nitric acid in sufficient amount to bring 
the solution to a clear amber color, and continue as di¬ 
rected on page 39. 

Determination of Alumina, Manganese, Lime and 
Magnesia. —Take 50 c.c. of the solution in a large beak 
er, add sodium carbonate until the fluid is nearly neutral 
and then to the clear red liquid add a solution of about 
5 grams of sodium or ammonium acetate; dilute to about 
500 c.c. with boiling distilled water. Heat to boiling for 
a minute or two, filter while hot and wash by decantation 
with hot water. Dissolve the precipitate in hot dilute 
hydrochloric acid, heat to boiling then add ammonia 
water to alkaline reaction. Filter and wash the precipi¬ 
tate with hot water. Ignite and weigh Fe 2 O s , A 1 2 0 3 , 
P 2 0 -. Calculate the per cent, of Fe 2 O s , Al 2 O s and P 2 0 5 . 
The per cent, of Al 2 O s is determined by subtracting the 
per cent, of Fe 2 0 3 and P 2 0 5 previously determined from 
the above. Add the filtrate and washings from the acetate 
precipitation to those from the precipitation by ammonia. 
Evaporate the solution to about 75 c.c. When cold add 
bromine water until the solution is strongly colored, add 


METALLURGICAL ANALYSIS 


61 


ammonia in excess and heat moderately for some time, 
then filter, wash with hot water. Test filtrate for man¬ 
ganese with more bromine and ammonia, he.at for some 
time and filter if necessary, dry, ignite and weigh Mn 3 0 4 . 
Calculate the per cent, of Mn 0 2 . 

Acidify the filtrate, from the manganese precipitate, 
with hydrochloric acid and concentrate to about ioo c.c. 
Add ammonia in slight excess, then precipitate the cal¬ 
cium with ammonium oxalate as calcium oxalate, 
CaC 2 0 4 . Filter, wash, ignite and weigh CaO. Calculate 
the per cent, of CaO. 

To the filtrate from the calcium oxalate add a volume 
of ammonia of sp. gr. .96, equal to one-sixth the volume 
of the solution. Then add hydrogen sodium phosphate 
drop by drop while stirring the solution with a glass rod, 
to precipitate the magnesium as ammonium magnesium 
phosphate. Allow to stand for some time, filter, wash 
with a mixture of one part of ammonia, sp. gr. .96, and 
three parts water, dry, ignite and weigh Mg 2 P 2 0 7 . Cal¬ 
culate the per cent, of MgO. 

Determination of the Sulphur. —To the remaining 50 
c.c. of the original solution add a few drops of hydro¬ 
chloric acid, heat to boiling in a beaker and precipitate 
the sulphur with barium chloride as barium sulphate, 
BaS 0 4 . Allow the precipitate to settle, filter, wash, ig¬ 
nite and weigh BaS 0 4 . Calculate the per cent, of sul¬ 
phur. 

Determination of Carbon Dioxide , Moisture, and Fer¬ 
rous Iron. See page 58. 


6 2 


METALLURGICAL ANALYSIS 


DETERMINATION OE TOTAL CARBON IN IRON 

AND STEEL. 


BY OXIDATION OF THE CARBON WITH CHROMIC ACID AND 
SULPHURIC ACID AFTER THE REMOVAL OF THE IRON. 

Treat about one gram of the pig iron or cast iron drill¬ 
ings in a number two beaker with a hundred c.c. of sat¬ 
urated solution (300 grams per liter) of copper potas¬ 
sium chloride and 7.5 c.c. of strong hydrochloric acid. 
For steel, treat about 3 grams in a number three beaker 
with 200 c.c. of the copper potassium chloride and 15 c.c. 
of strong hydrochloric acid. Stir the solution vigorously 
for a few minutes, place the beaker in a warm place, but 
not where the temperature can rise above 6o° or 70°C 
Continue to stir at frequent intervals until the precipi¬ 
tated copper is dissolved. Reactions are: 

Fe+CuCl 2 =FeCl 2 +Cu 

Cu-FCuC 1 2 = 2 CuC 1 . 

xAllow the undissolved residue to subside and then fil¬ 
ter through an ignited asbestos filter. The filter may be 
made by placing a small perforated platinum or porcelain 
disc in the bottom of a small funnel, and upon it is placed 
in the usual manner the asbestos which has been previ¬ 
ously ignited. Wash the residue at first with a little di¬ 
lute hydrochloric acid and then with hot water. 


METALLURGICAL ANALYSIS 


6z 


OXIDATION OF THE CARBONACEOUS RESIDUE. 
Apparatus required : 

i. A flask, A, (see Fig. i), having a capacity of about 



300 c.c. provided with a double perforated rubber stop¬ 
per. Through one of the holes is passed a separating 
funnel, B, with glass stopcock. The funnel should have 
a capacity of about 100 c.c. Through the other hole of 
the stopper is passed a condenser, C, through which a 
stream of water continually passes while the combustion 
is being made. 

II. An apparatus, D, for the purification of the air. 
This consists of a U tube filled partly with pieces of solid 
potassium hydroxide and partly with granular calcium 
chloride. 

III. A series of connected U tubes in which the car¬ 
bon dioxide is dried and purified before entering the 
weighed absorption apparatus. 

E contains a solution of silver sulphate and concen¬ 
trated sulphuric acid. 















































64 


METALLURGICAL ANALYSIS 


F, a U tube filled with pumice stone which has been 
saturated with a concentrated solution of copper sul¬ 
phate, and then heated to dehydrate the salt. 

G, a U tube filled with granular calcium chloride. 

IV. An' apparatus, H, for the absorption of carbon 
dioxide, containing a solution of potassium hydroxide, 
sp. gr. 1.27 (two parts KOH to three parts H 2 0 ). This 
absorption apparatus is connected with a tube, I, partly 
filled with granular calcium chloride and partly with soda 
lime. This tube is to protect H from carbon dioxide and 
moisture of the air. 

Process .—Transfer the asbestos filter and carbonace¬ 
ous residue to the combustion flask A. If necessary clean 
the funnel with a little ignited asbestos and place it in 
the flask with the residue. Weigh the apparatus for the 
absorption of the carbonic acid gas and connect .it prop¬ 
erly with the tubes G and I. Add through the separat¬ 
ing funnel 10 c.c. of a saturated solution of chromic acid, 
and then slowly add 100 c.c. of concentrated sulphuric 
acid, which has been heated nearly to the boiling point 
with a little chromic acid, and then cooled. Pass a slow 
current of air through the whole apparatus and very 
gradually raise the temperature of the liquid in the flask 
nearly to the boiling point. The reaction is: 

3C+4CrO,-f 6H 2 S0 4 =2Cr 2 (S 0 4 ) 8 + 3 C 0 2 + 6 H a 0 . 

When the oxidation is complete, gradually lower the 
light while a current of air continues to pass. Extin¬ 
guish the light and when about one liter of air has passed 
through the apparatus after the extinguishing of the 
flame, detach and weigh the carbon dioxide absorption 
apparatus. The increase in weight is C 0 2 . Calculate 
per cent, carbon. Results should agree within .01 per 
cent. 


METALLURGICAL ANALYSIS 


65 


DETERMINATION OF TOTAL CARBON IN IRON 

AND STEEL. 

BY COMBUSTION OF THE CARBON IN THE SHIMER CRUCIBLE 
AFTER THE REMOVAL OF THE IRON. 

Separate the iron from the carbon as directed in the 
preceding* experiment. Dry the carbonaceous residue in 
an air bath for about half an hour at ioo°C. When dry, 
transfer it to the Shinier crucible with the carbon side 
down. It is well to have a circular piece of thin plati¬ 
num foil in the bottom of the crucible. The carbon 
should all be kept within one-fourth of an inch of the 
bottom of the crucible, otherwise a part of the carbon 
might escape combustion. 

Partly fill the crucible with ignited asbestos. 



The Shinier crucible is a special water-jacketed plati¬ 
num crucible closed by a hollow water-cooled metal stop¬ 
per made gas-tight by means of a rubber band. See big. 
2. Place the rubber band around the crucible stopper 
and insert it in the crucible. 

The crucible is supported by passing it about half-way 
through a heavy piece of asbestos board. The crucible 
































66 


METALLURGICAL ANALYSIS 


is connected by means of the water inlet tube, with a 
water supply for cooling die stopper. Under the cruc¬ 
ible is an upright Bunsen burner or blast lamp. If the 
carbonaceous matter is mainly graphite it will require the 
strong heat of a blast lamp to make the combustion. 

Connected with the air inlet tube is Geissler’s bulb con¬ 
taining solution of potassium hydroxide (sp. gr. 1.27) 
for purification of the air. Between the Geissler bulb 
and the crucible is a small guard bottle to retain any 
drops of the potassium hydroxide that may be forced 
over from the Geissler apparatus. 

An aspirator to furnish air pressure is connected with 
the Geissler bulb. Next to the crucible and connected to 
it by means of the air outlet tube is a short brass tube 
containing cupric oxide in its' central portion and pro¬ 
vided with wet wick at the ends for cooling purposes. 
Next to the cupric oxide tube is a glass tube filled with 
glass beads, wet with distilled water, for retaining hydro¬ 
chloric acid and chlorine. 

Next to the glass bead tube is attached a large calcium 
chloride tube. 

The calcium chloride tube is connected with a weighed 
Geissler bulb contaning potassium hydroxide (sp. gr. 
1.27) and the Geissler bulb with a guard tube of calcium 
chloride. 

Be sure that the water is running from the stopper and 
that the cupric oxide tube is red hot for from one and 
one-half to two inches in its central part, then turn on 
the air at the speed of about three bubbles per second 
and bring a small blast-lamp flame immediately under the 
crucible, so as to heat the bottom to a bright red heat, ex¬ 
tending at least one-fourth inch from the bottom. A large 


METALLURGICAL ANALYSIS 


67 


flame should be avoided. Time required for making com¬ 
bustion about twenty-five minutes. 

References : 

1\ W. Shimer, Jour. Am. Chcm. Hoc., Vol. XXI, page 557 : and 
Vol. XXIII, page 227 ; and Vol. XXV, page 997. 

G. Auchy, Jour. Am. Clicm. Hoc., Vol. XXIV, page 1206. 

J. V. R. Stehman, Jour. Am. Chcm. Hoc., Vol. XXV, page 237. 

DETERMINATION OF GRAPHITIC CARBON IN 

IRON. 

METHOD I. 

Dissolve one gram of pig iron in 15 c.c. of nitric acid 
of sp. gr. 1.2. Collect the undissolved material upon an 
ignited asbestos filter and wash with hot water. Treat 
the residue on the filter with a hot solution of potassium 
hydrate of 1.1 specific gravity. Wash thoroughly with 
hot water, then with a little dilute hydrochloric acid and 
finally with cold water. Oxidize the carbon to carbon di¬ 
oxide with chromic and sulphuric acids. See pages 63 
and 65. 

A very satisfactory result may be obtained as follows: 
Place the asbestos filter and graphite in a platinum cruc¬ 
ible. Dry the crucible and contents at ioo°C., cool and 
weigh. Pleat over a Bunsen burner until the graphite is 
all burned off and weigh again. The loss of weight gives 
graphite. 

method II. 

Dissolve 2 grams of pig iron in 50 c.c. of dilute nitric 
acid (sp. gr. 1.2) in a number four beaker, heat gently 
to boiling and then boil for about five minutes. Next 
add about 1 c.c. hydrofluoric acid, being careful not to 
allow it to touch the glass. Immediately give the beaker 


68 


METALLURGICAL ANALYSIS 


an oscillatory motion, heat a few minutes, dilute with 
water and filter onto a filter paper which has been dried 
at ioo°C. and then weighed. Wash at .first with hot 
water and then two or three times with dilute hydro¬ 
chloric acid. Wash again with water and then twice with 
ammonia and finally several times with water. Dry the 
filter paper and graphite at ioo°C. and weigh. Calcu¬ 
late per cent, graphite. If extreme accuracy is required, 
place 'the dried and weighed paper and graphite in a 
platinum crucible and thoroughly burn ofif paper and 
graphite and weigh the siliceous residue. This weight 
of silica should be multiplied by 1.06 and the product de¬ 
ducted from the weight of graphite as found above. 

References : 

1’. W. Shinier, Jour. Am. Chevn. Soc., Vol. XVII, page 873. 

G. Auchy, Jour. Am. Chem. Soc., Vol. XXII. page 47. 

F. Jj. Crobough, Jour. Am. Chem. Soc:, Vol. XVI, page 104. 

G. T. Dougherty, Chem. News, Sept. 8. 1899. 

T. M. Drown, Trans. Am. Inst. Min. Engrs., Vol. II, page 224. 

DETERMINATION OF COMBINED CARBON. 

EGGERTZ COLORIMETRIC METHOD. 

The method depends upon the fact that when samples 
of similar varieties of steel or iron are dissolved in nitric 
acid (sp. gr. 1.2 ) the depth of the brown color produced 
is directly proportional to the amount of chemically com¬ 
bined carbon in the samples. The combined carbon in 
a sample of steel may be determined by comparing the 
color produced upon dissolving a known weight of the 
sample in nitric acid with the color produced by dissolv¬ 
ing a weighed quantity of similar steel whose percentage 
of combined carbon has been very accurately determined 
by the combustion method. See page 62. 


METALLURGICAL ANALYSIS 


69 


Process. —Clean, dry and number several test tubes. 
Weigh into one .2 gram of standard steel and into the 
other the same amount of each sample to be tested. Add 
to each tube the required amount of nitric acid of sp. gr. 
1.2. 

For steels containing less than .3% combined carbon 
use 3 c.c. HN 0 3 S P- fe r - I - 2 - 

For steels containng .3-.5% combined carbon use 4 
c.c. FINO., sp. S v ' 1.2. 

For steels containing .5-.8% combined carbon use 5 
c.c. HNO a sp. gr. 1.2. 

For steels containing .8-1% combined carbon use 6 
c.c. HN 0 3 sp. S' 1 *- I - 2 - 

For steels containing 1% and over combined carbon 
use 7 c.c. HN 0 3 sp. gr. 1.2. 

Place a small funnel in the mouth of each test tube. 
Heat them in a water bath, shaking them from time to 
time, until all of the carbonaceous matter is dissoAed. 
Remove each test tube and place it in a cold water bath 
as soon as the solution becomes clear. When cold pour 
the solution of the standard steel into an Eggertz grad¬ 
uated comparison tube. Wash out the test tube with a 
few drops of nitric acid (sp. gr. 1.2). Dilute the solu¬ 
tion with water to about twice the volume of the acid 
which was used in making it. To save time in making 
calculation it is best to dilute the solution to some con¬ 
venient multiple of the carbon contents of the steel. Sup¬ 
pose that the standard steel contains .35 per cent, com¬ 
bined carbon, dilute the solution to 7 c.c. Then each c.c. 
equals .05 per cent, carbon. Next pour the solution of 
a sample to be tested into another Eggertz tube, and di¬ 
lute it until the color is the same as in the standard. Sup- 


70 


METALLURGICAL ANALYSIS 


pose that 8 c.c. is the dilution of the sample, then it con¬ 
tains .4 per cent, of combined carbon. 

References : 

Trans. Am. Inst. Min. Engs., Vol. I, page 240. 

Trans. Am. Inst. Min. Engs., Vol. XVI, page 111. 

Chem. News, Vol. XLVII, page 285. 

G. Auchy, Jour. Am. Chem. Sac., Vol. XXV, page 99i>. 

DETERMINATION OF PHOSPHORUS IN IRON 

AND STEEL. 

Treat about two grams of the borings with 75 c.c. of 
nitric acid (sp. gr. 1.135), 1 part concentrated HNO s , 
and 3 parts water, in a 400-500 c.c. Erlenmeyer flask and 
heat gently. When the first action is over boil for one 
or two minutes. Add 10 c.c. of potassium permangan¬ 
ate solution (containing 123/2 grams of KMn 0 4 per 
liter), and boil until the pink color disappers. A pre¬ 
cipitate of manganese oxide is formed. Remove the 
flask from the heat and add a little ferrous sulphate (free 
from phosphate) or sugar and shake the flask until the 
precipitate of manganese dioxide dissolves. L T se as lit¬ 
tle excess of the ferrous sulphate or sugar as possible. 
If the sample contains much graphite it is best to filter it 
off. To the solution add ammonia until the mass sets to 
a stiff jelly. Then add HNCX, Con. to get amber color. 
Heat the solution in the flask to 85 °C. and add about 50 
c.c. ammonium molybdate solution, to precipitate the 
phosphorus as ammonio-phospho-molybdate. Determine 
the phosphorus in the yellow precipitate by the Emmer- 
ton method, page 39, or by the acidimetric method, page 
4L 

Note.—White irons and some malleable cast irons con¬ 
taining considerable combined carbon require that the 


METALLURGICAL ANALYSIS 


/I 


above process be modified in such a way as to destroy 
the organic matter. This can be accomplished by evapor¬ 
ating the nitric acid solution of the sample to complete 
dryness in a porcelain casserole and heating the residue 
until it ceases to give off red fumes. Allow to cool, add 25 
c.c. of concentrated hydrochloric acid and heat to redis¬ 
solve the residue and evaporate to about 10 c.c. Add 20 
c.c. of concentrated nitric acid and again evaporate to 10 
c.c. next add a little water and filter if necessary. Heat 
the solution to 85°C., precipitate the phosphorus with 
ammonium molybdate and proceed as above. 

Different chemists working on the same sample should 
agree within .005 per cent. 

References : 

Dudley & Pease, Jour. Am. Chem. goc., Vol. VII, pages 10S & 519. 

Clemens Jones, Jour. An. & Appl. Chem., Vol. IV, page 2GS. 

DETERMINATION OF MANGANESE IN IRON 

AND STEEL. 

volhard’s method. 

Take one gram of the borings. Dissolve the sample 
in 15 c.c. of nitric acid (sp. gr. 1.2) in a casserole. When 
solution is complete add 10 c.c. dilute sulphuric acid and 
evaporate to dryness, and heat the residue until heavy 
white fumes of sulphuric acid are evolved to destroy car¬ 
bonaceous matter. Allow the dish to cool, add 100 c.c. 
water, and heat until the ferric sulphate is dissolved 
Wash the contents of the casserole into a half liter flask 
with cold water, nearly neutralize with carbonate of soda, 
and proceed from this point as directed in the analysis 
of iron ores, page 44. Different chemists, working on 
the same sample, should agree within .01 per cent. 


72 


METALLURGICAL ANALYSIS 


DETERMINATION OF MANGANESE IN IRON AND STEEL BY 

FORD-WILLIAMS METHOD. 

Weigh one to five grams of the iron or steel and dis¬ 
solve in nitric acid (sp. gr. 1.2). Use about 15 c.c. of 
the acid for every gram of iron or steel taken. In case 
of pig iron, filter off the graphite through an asbestos fil¬ 
ter. Evaporate to about 10 c.c. Now add 75 c.c. of 
strong nitric acid and heat. When solution is warm add 
about 5 grams of potassium chlorate and boil. From 
this point proceed as in the analysis of iron ores; page 46. 

THE COLOR METHOD FOR MANGANESE IN IRON AND STEEL. 

Weigh out .2 gram of each sample and the standard. 
If the samples to be analyzed be pig iron, then use a pig 
iron standard, and if the sample is steel, a steel standard. 
Place the weighed portions in 10 inch test tubes properly 
numbered. Pour into each 20 c.c. of nitric acid (sp. gr. 
1.2). Place in the mouth of each test tube a small fun¬ 
nel. Heat in the water bath at ioo°C. until solution is 
complete. Add 10 c.c. of water, heat in a calcium chlor¬ 
ide bath (which boils at H5°C.) to boiling, add about 
3 grams of lead dioxide (Pb 0 2 ) and continue boiling for 
just five minutes. The reaction is: 

2Mn (NO a ) 2 + 5 Pb 0 2 +6HNO s = 

5 Pb (N 0 3 ) 2 +2 PI 2 0 -}- 2 H M n 0 4 . 
Place the tubes in cold water, and when the insoluble 
matter settles, decant the clear solutions into the reading 
tubes and compare. 

DETERMINATION OF SULPHUR IN IRON AND 

STEEL. 

Method /.—Weigh 5.4936 grams of the drillings into 


METALLURGICAL ANALYSIS 


73 


a number 3 beaker. Add slowly a mixture of 50 c c 
concentrated nitric acid and one c.c. concentrated hydro¬ 
chloric acid. Heat gently if the reaction does not begin 
in the cold, but remove from the heat and place the beak¬ 
er in cold water if the reaction is too violent. If any of 
the sample resists solution add a few drops of concen¬ 
trated hydrochloric acid from time to time. Add a little 
carbonate of soda, and evaporate to complete dryness. 

The carbonate of soda is added to form sodium sul¬ 
phate and thus prevent loss of sulphur trioxide, from the 
decomposition of iron sulphate in case the residue is 
overheated. Add 30 c.c. of concentrated hydrochloric 
acid and evaporate to about 5 c.c. Add water, heat, and 
filter off the silica. Heat the filtrate to boiling and add 
10-20 c.c. of a hot solution of barium chloride (1 to 10). 
Allow the precipitate to settle, filter, wash with a little di¬ 
lute hydrochloric acid and then with hot water, ignite 
and weigh barium sulphate. The weight of the precipi¬ 
tate in milligrams divided by four and mulitplied by ten 
gives the per cent, of sulphur. 

Method II—Evolution Method .—The process consists 
in liberating the sulphur from the iron or steel by means 
of dilute hydrochloric acid, in the form of hydrogen sul¬ 
phide and absorbing the gas in an ammoniacal solution 
of cadmium chloride, as cadmium sulphide. The sulphur 
is afterward liberated from the cadmium sulphide as hy¬ 
drogen sulphide by means of hydrochloric acid and the 
hydrogen sulphide titrated with a standard solution of 
iodine. 

Apparatus required .—A flask, A, of about 3 00 c - c - 
capacity, provided with a doubly perforated rubber stop- 


74 


METALLURGICAL ANALYSIS 


per. See Fig. 3. Through one of the holes is passed 
a separating funnel, B, and through the other hole is 
passed a bent tube, D, extending to within two or three 
inches of the bottom, of an eight inch test tube, C. 



Fig. 3. 

Solutions Required. —I. Ammoniacal Solution of Cad¬ 
mium Chloride; prepared as follows: Dissolve 13 grams 
of cadmium chloride in water, add 65 c.c. of strong am¬ 
monia and dilute to a volume of one liter. 

II. • Standard Iodine Solution, of such strength that 
one c.c. is equivalent to .0005 gram of sulphur. The re¬ 
action between the hydrogen sulphide and the iodine is: 

H 2 S+2l=2HI+S. 

Then 

At. wt. of S : 2 (at. wt. of I) =.0005 : x. 

32 : 253.7 : : .005 : x. 

X=.003965 gram of iodine, the amount required to be 
present in each cubic centimeter of the iodine solution, 
or 3.965 grams per liter. The solution may be prepared 
from decinormal solution of iodine by taking 313.3 c c. 
diluting with water to one liter. 













METALLURGICAL ANALYSIS 


75 


The solution may be prepared from iodine as follows: 
Weigh four grams of iodine and place it in a mortar 
with about six grams of potassium iodide and triturate 
with small portions of water until all is dissolved. Dilute 
the solution to one liter volume and mix thoroughly. 
Standardize the solution by means of a standard solu¬ 
tion of sodium thiosulphate, containing about eight 
grams of the salt per liter; the exact strength of which 
may be determined by means of standard potassium bi¬ 
chromate or permanganate solution as follows: Take 
io c.c. of the potassium bichromate solution in a number 
4 beaker, add a little water and about one gram of po¬ 
tassium iodide. Add a little hydrochloric acid and stir 
a few moments. The reaction is: 

K 2 Cr 2 0 7 + 6 KI+i 4 HCl= 8 KCl+ 2 CrCl 3 + 6 I+ 7 H 2 0 . 

Dilute with water and titrate the liberated iodine with 
the thiosulphate solution using starch indicator, toward 
the end of the reaction. The reaction is: 

2l+2Na 2 S 2 0 3 =2NaI+Na 2 S 4 0 6 . 

Calculate the strength of the thiosulphate solution. 
Now fix the strength of the iodine solution from the 
standard thiosulphate solution by titration, using the 
starch indicator. Dilute the iodine solution with water 
to the strength of i c.c.=.0005 gram sulphur. 

Process .—Weigh into flask A 5 grams of the drillings. 
Place in the test tube C, about 10 c.c. of the cadmium 
chloride solution and add water until the test tube is 
about two-thirds full. Connect the test tube with the 
generating flask A. Slowly add by means of the sep¬ 
arating funnel, 75 to 100 c.c. of dilute hydrochloric acid 
(sp. gr. 1.1) to the drillings. When about all of the 
drillings are dissolved heat to boiling a few minutes, and 


/6 


METALLURGICAL ANALYSIS 


before removing the heat disconnect the test tube, or open 
the stop cock of the separating funnel. 

Pour the contents of the test tube into a large beaker, 
dilute to about 400 c.c. Acidify the solution with hydro¬ 
chloric acid and titrate with the standard iodine solution, 
using the starch indicator. Do not wait for the precipi¬ 
tate of cadmium sulphide to dissolve before commencing 
the titration. 

Each cubic centimeter of the iodine solution required 
equals .01 per cent, of sulphur. Results on the same 
sample, obtained by different analysis, should agree 
within .005 per cent. 

References : 

Am. Chem Jour., Vol. XXVII, page 500. 

(I. Auchy, Jour. Am. Chem. Hoc., Vol. XVIII. page 400. 

G. Auchy, Jour. Am. Chem. Hoc., Vol. XXIII, page 147. 

F. C. Phillips, Jour. Am. Chem. "Soc., Vol. XVIII, page 1079. 

F. C. Phillips, Jour. Am. Chem. Hoc., Vol. XVII, page 891. 

A. A. Blair, Jour. Am. Chem. Hoc., Vol. XIX, page 114. 

T. M. Drown, Trans. Am. Inst. Min, Engrs., Vol. X, page 187. 

T. M. Drown, Trans. Am. Inst. Min. Engrs., Vol. II. page 224. 

T. M. Drown, Trans. Am. Inst. Min. Engrs., Vol. XII, page 507. 

C. B. Dudley, Jour. Am. Chem. Hoc., Vol. XV, page 514. 

bamber's METHOD FOR SULPHUR IN PIG IRON. 

Dissolve 5 grams in strong nitric acid, add two to five 
grams of potassium nitrate, evaporate to dryness in a 
platinum or porcelain dish, and ignite. Treat with water 
with the addition of a little sodium carbonate, filter, and 
wash with water containing a little sodium carbonate, 
Acidulate with a little hydrochloric acid, evaporate to 
dryness, redissolve in water with a few drops of hydro¬ 
chloric acid, and precipitate boiling with barium chlor¬ 
ide. Method suitable for pig iron containing sulphur in 
such a form that it is not acted upon by IT NO.., HC 1 or 
aqua regia. 

Reference : 

G. Auchy, Chem. Ertg; Vol. Ill, page 318. 


METALLURGICAL ANALYSIS 


77 


wiborgh's color method for sulphur in iron and 

STEEL. 

Weigh .8 to i gram of the drillings into the generat¬ 
ing flask A, (See Fig. 4) and fill the flask about one- 
third full of water. The cylinder B, is then adjusted, 
and the water in the flask heated to boiling. A rubber 
washer, C, is then placed on top of the cylinder, followed 
by the prepared cloth, D, (saturated with a solution of 
cadmium chloride), the second rubber washer, E, and 
the wooden ring, F, the whole being firmly clamped to¬ 
gether by two steel clamps, G. 



Fig. 4. 

Be sure that the top of the cylinder is in a horizontal 
position. Heat the flask, and as soon as the cloth is 
moistened and the air driven out of the apparatus, admit 
about 12 c.c. of dilute sulphuric acid (1 to 4) through 
the side tube H, and apply gentle heat, till the sample is 

9 

) p 

0 > > 

> > 

) » > 
















78 


METALLURGICAL ANALYSIS 


in solution. The cloth is then removed, dried on a blot¬ 
ting or filter paper and compared with the standard 
colors. 

References : 

Jour. Am. Chcm. Soc., Vol. VI, page 301. 

F. I‘. Treadwell, Analytischen Chemie ., Vol. II, page 227. 

DETERMINATION OF SILICON IN PIG IRON , 
CAST IRON AND STEEL. 

Drown's Method.— Treat one gram of the pig or cast 
iron drillings in a four inch casserole with 30 c.c. of sili¬ 
con mixture ( i part concentrated H 2 S 0 4 and 5 parts 
HN 0 3 S P- & r - I - 2 )- For steel treat about 5 grams of the 
drillings with 100 c.c. of silicon mixture. Cover the dish 
with a glass cover. At first keep the dish well covered, 
but after the violent action ceases, pull the cover a little 
to one side and evaporate until fumes of sulphur tri¬ 
oxide appear. Cool, add from 150 to 200 c.c. of water 
and a little hydrochloric acid. Heat to dissolve the fer¬ 
ric sulphate, filter hot, wash with dilute hydrochloric 
acid, and then with hot water, ignite, cool and weigh 
Si 0 2 . Calculate the per cent, of silicon. 

The silica should be perfectly white. If it is colored 
with oxide of iron, after weighing it, add two or three 
drops of concentrated sulphuric acid and four or five c.c. 
of hydrofluoric acid. Evaporate to dryness, ignite, cool 
and weigh again. The loss of weight gives the amount 
of silica. 

Calculate the per cent, of silicon. 

Chemical analyses of the same sample made by differ¬ 
ent chemists should agree within .01 per cent. 


METALLURGICAL ANALYSIS 


79 


Chromic Acid Modification of Drown’s Method for 
Silicon in Pig Iron. —Treat one gram of the pig iron in 
a 4 inch casserole with io to 20 c.c. of water and 25 c.c. 
of silicon mixture (1 part H 2 S 0 4 , sp. gr. 1.84 and 2 parts 
HN 0 3 , sp. gr. 1.2). Heat gently until the violent action 
ceases. When dissolved, evaporate rapidly until the iron 
sulphate becomes insoluble, and commences to spatter 
against the cover glass. Remove from the lamp and while 
hot add 15 c.c. of a water solution of chromic acid (120 
gr. per liter.) Boil again as before until the chromic acid 
crystallizes out. Remove from the lamp and add hot 
water, slowly at first, boil for a few minutes or until dis¬ 
solved and clear. Filter, wash the chromic acid out of 
the filter with hot water, wash once with hydrochloric 
acid (sp. gr. 1.06) and then wash three or four times 
with hot water. Ignite, cool and weigh Si 0 2 . Calcu¬ 
late the per cent, of Si. 

Precautions. —The evaporation with the chromic acid 
must not be carried too far, otherwise insoluble salts are 
formed. On the other hand if the heat is not continued 
long enough, the graphite will not be oxidized. The 
small amount of graphite occasionally remaining is very 
rapidly burned off in the ignition. A slight green tint 
in the ash does not materially affect the result. This 
treatment with chromic acid not only removes the car¬ 
bon, but renders the filtration much more rapid. Time 
required, from 20 to 30 minutes. 


References : 

T. M. Drown, Trans. Am. Inst. Min. Engrs., Vol. VII, page 346. 
D. II. Brown, Jour. Anal, if- App. Chem., Vol. VI, page 452. 


8o 


METALLURGICAL ANALYSIS 


DETERMINATION OF ALUMINUM IN IRON 

AND STEEL . 

Treat i gram of the iron or steel in a number 3 beak¬ 
er, with a mixture of 15 c.c. of nitric acid (sp. gr. 1.2) 
and 10 c.c. of hydrochloric acid (sp. gr. 1.1). Cover the 
beaker with a glass cover and heat until sample is dis¬ 
solved. Remove the cover and evaporate to dryness. 
Take up in 15 c.c. of concentrated hydrochloric acid, di¬ 
lute, filter on ashless fdter paper, and wash with water. 
Add 20 c.c. of a 10% solution of hydrogen sodium phos¬ 
phate and continue as in the determination of alumina in 
iron ores. See page 52. 

Calculate per cent, of aluminum. 


1907 . 


International Atomic Weights. 

o 




0-16. 



o 

II 

—X 

cr> 

Aluminum. 

. . . . A1 

27.1 

Neodymium. 

. . . Nd 

143.6 

Antimony. 

. ...Sb 

120.2 

Neon. 

. . . Ne 

20 

Argon. 

.... A 

39.9 

Nickel. 

. . . Ni 

58.7 

Arsenic. 


75.0 

Nitrogen. 

. . . N 

14.0 

Barium. 

. ...Ba 

137.4 

Osmium. 

. . . Os 

191 

Bismuth. 

.... Bi 

208 

oxygen. 

. . . O 

16.00 

Boron. 

. . . . B 

11 

Palladium. 

. . . Pd 

106.5 

Bromine. 

.... Br 

79.96 

Phosphorus. 

. . . P 

31.0 

Cadmium. 

_Cd 

112.4 

Platinum. 

. . . l't 

194.8 

Caesium. 

. . . . Cs 

132.9 

Potassium . 

. . . Iv 

39.15 

Calcium . 

_ Ca 

40.1 

Praseodymium . . 

. . Pr 

140.5 

Carbon . 

. . . .C 

12.00 

Radium . 

. . Rd 

225 

Cerium. 

. . . . Ce 

140.25 

Rhodium. 

. . fih 

103.0 

Chlorine. 

. . . .Cl 

35.45 

Rubidium . 

. . . Rb 

85.5 

Chromium . 

. . .. Cr 

52.1 

Ruthenium . 

. . . Ku 

101.7 

Cobalt . 

... Co 

59.0 

Samarium . 


150.3 

Columbium . 

. .. .Cb 

94 

Scandium . 

. . . Sc 

44.1 

Copper . 

.. . . Cu 

63.6 

Selenium . 

. . . Se 

79.2 

Erbium . 

.... Er 

166 

Silicon . 

. . Si 

28.4 

Fluorine . 

. . . . F 

19 

Silver . 

. . . Ag 

107.93 

Gadolinium .... 

. . . Gd 

156 

Sodium . 

. . Na 

23.05 

Gallium. 


70 

Strontium. 

. . Sr 

87.6 

Germanium.... 

. . . . Ge 

72.5 

Sulphur. 

. . S 

32.06 

Glucinum. 

. . . . G1 

9.1 

Tantalum . 

. . . Ta 

183 

Gold . 


197.2 

Tellurium . 

. . . Te 

127.6 

Helium . 

. . . . ITc 

4 

Terbium . 

. . . Tb 

160 

Hydrogen . 

. ... II 

1.008 

Thallium . 

. . T1 

204.1 

Indium . 

.... In 

115 

Thorium . 

. . . Th 

232.5 

Iodine . 

. . . . I 

126.97 

Thulium . 

. . . Tin 

171 

Iridium . 

... Ir 

193.0 

Tin. 


119.0 

Iron . 

. . . Fe 

55.9 

Titanium. 

. . Ti 

48.1 

Krypton . 

. . . . Ivr 

81.8 

Tungston.. . 

. . W 

184 

Lanthanum. . . . 

... La 

138.9 

Uranium. 

. . .V 

238.5 

Lead . 

- Pb 

206.9 

Vanadium . 

. . V 

51.2 

Lithium . 

... Li 

7.03 

Xenon . 

. .. Xe 

12S 

Magnesium . 

.... Mg 

24.36 

Ytterbium . 

. . Yb 

173.0 

Manganese . 

. . . . Mn 

55.0 

Yttrium . 

. . Yt 

89.0 

Mercury . 

• • • • Hg 

200.0 

Zinc . 

. . .Zn 

65.4 

Molybdenum . . . . 

... Mo 

96.0 

Zirconium. 

. . Zr 

90.6 































































































INDEX 


Alumina, in iron ores, determination of . . . . 52 

Alumina, in slags, determination of ... 21, 26 

Aluminum, in iron and steel, determination of . . 80 

Ammonium molybdate, reagent.39 

Ammonium molybdate solution, method of standardizing 12 

Arsenic, in arsenic ores, determination of ... 13 

Barium, in slags, determination of .... 18 

Calcium, in iron ores, determination of . . . . 61 

Calcium, in slags, determination of 

by Gravimetric method ..... 23 

Volumetric method ...... 18 

Carbonic acid gas, in iron ores, determination of . 58 

Carbon, total, in iron and steel, determination of 

by Chromic acid method ..... 62 

by combustion in the Shimer crucible . . 65 

Carbon, combined, in iron and steel, determination of 

by the Color method.68 

Carbon, graphitic, in iron and steel, determination of . 67 

Coal and coke, methods for the analysis of . . . 28 

Chromium, in chrome ore, determination of . . . 15 

Copper, in copper ores, determination of 

by the Iodide method ...... 1 

by the Cyanide method.4 

by the - Electrolytic method ..... 6 

by the Color method.7 

Copper, in slags, mattes, etc., determination of . 19, 25 

Ferrous oxide, in iron ores, determination of . . 58 

Ferrous sulphate solution, method of standardizing. 16. 47 
Iodine solution, method of standardizing ... 74 

Iron, in iron ores, determination of 

by Standard solution of KMnO + .... 34 

by Standard solution of K. > Cr 0 0 ? .... 35 

Iron ores, method for complete analysis of . . . 59 

Jones’s reductor, use of, in determining phosphorus . 41 

Lead, in lead ores, determination of, by Alexander’s 

method ......... 12 

Lead, in slags, mattes, etc. determination of . . 19, 25 

Manganese, in iron ores, determination of 

by Volhard’s method ...... 44 

by Ford-Williams’ method. 4 .^ 

by Julian’s method.48 



84 


INDEX 


71 

72 
72 
72 

22, 27 
58 

42 

37 

4i 

43 
70 
21 


Manganese, in iron and steel, determination of 
by Volhard’s method .... 

by Ford-Williams’ method 
by Julian’s method .... 

by Color method ..... 

Manganese, in slags, determination of . . .19 

Moisture, in iron ores, determination of 
Nitric acid, method of preparing a standard solution 
Phosphorus, in iron ores, determination of 
by Emmerton’s method 
by the Acidimetric method 
by Wood’s method .... 

Phosphorus, in iron and steel, determination of 
Phosphorus, in slags, determination of 
Potassium permanganate solution, method of standardizing 34 
Potassium bichromate solution, method of standardizing 35 
Potassium ferrocyanide solution, method of standardizing 8 
Potassium cyanide solution, method of standardizing . 4 

Potassium sulphocyanate solution, method of standardizing 14 
Potassium hydroxide, method of preparing standard solu¬ 
tion .42 

Silica, in ores, determination of ..... 50 

Silica, in slags, determination of . . . . 17, 19, 24 

Silicon, in iron and steel, determination of . . . 78 

Slags, methods for the analysis of . . . 17, 19, 24 

Sodium hydroxide, method of preparing a standard solution 42 
Sodium thiosulphate, method of preparing and stand¬ 
ardizing .. . . . 1, 74 

Sulphur, in iron ores, determination of ... 49 

Sulphur, in slags, determination of . . . . 23, 28 

Sulphur, in coal and coke, determination of . . 31 

Sulphur, in iron and steel, determination of 

by Oxidation and Solution.72, 76 

by Evolution method ...... 73 

by Wiborgh’s color method 77 

Titanium, in iron ores, determination of ... 53 

by Gooch’s method.53 

by Bettel’s method.55 

by Weller’s color method .... 57 

Zinc, in zinc ores, determination of, by Low’s method . 8 

Zinc, in zinc ores, determination of, by Waring’s method 11 

Zinc, in slags, determination of.26 





































- 












J 




t 


















